Impact of D3 lymph node dissection on survival for patients with T3 and T4 colon cancer

Oncologic safety of transverse colon cancer surgery without central vessel ligation of middle colic artery

BACKGROUND

Surgical standardization for transverse colon cancers (TCC) has not been established, and the oncologic benefit of central vessel ligation (CVL) are still unclear. This study aimed to evaluate the oncologic safety of TCC surgery without CVL of the middle colic artery (MCA).

METHODS

This is a single-center, retrospective, observational, comparative study. The clinical, surgical, and pathological characteristics of the patients who underwent radical surgery for non-metastatic TCC between January 2012 and December 2020 were investigated, and the characteristic and oncologic outcomes of No CVL and CVL groups were compared.

RESULTS

The number of No CVL and CVL groups was 47 (44.3%) and 59 (55.7%), respectively. There was no statistically significant difference between the two groups in surgical complications, stage, mean number of retrieved lymph nodes (LN) (24.12 vs. 22.36 p = 0.464), mean number of metastatic LN (1.53 vs. 0.74, p = 0.163), mean proximal margin (19.2 cm vs. 16.7 cm, p = 0.139), mean distal margin (9.6 cm vs. 9.9 cm, p = 0.753), adjuvant chemotherapy, total recurrence rate (6.4 vs. 11.9%, p = 0.507), lymphatic recurrence rate (0.0% vs. 5.1%, p = 0.253), and local recurrence rate (2.1 vs. 1.7%, p = 0.984). Furthermore, there was no statistically significant difference of 5-year disease-free survival (DFS) and overall survival (OS) in stage II (DFS: 94.4 vs. 91.3%, p = 0.685, OS: 94.1 vs. 95.5%, p = 0.838) and stage III (DFS: 88.5 vs. 68.4%, p = 0.253, OS: 100.0% vs. 79.7, p = 0.328).

CONCLUSION

TCC surgery without CVL of the MCA showed comparable surgical and oncologic outcomes compared to surgery with CVL. Therefore, preservation of a branch of the MCA may be considered a safe option, when combined with adequate lymph node dissection, if necessary. A large, prospective, and controlled study will be necessary to provide solid evidence of the oncologic safety of this procedure.

Risk factors affecting delay of initiating adjuvant chemotherapy for stage III colorectal cancer

PURPOSE

Delay in initiating adjuvant chemotherapy (AC) after curative resection of colorectal cancer (CRC) has been reported to lead to poor prognosis, but few studies have looked at associated factors. This study aimed to identify risk factors for delay in initiating AC.

METHODS

Data from 200 consecutive patients who underwent curative resection and AC for stage III CRC between 2013 and 2018 were retrospectively collected and analyzed.

RESULTS

AC was initiated more than 8 weeks after surgery in 12.5% of patients (the delay group). Compared to those with no delay (the non-delay group), patients in the delay group had significantly higher rates of synchronous double cancers (2.3% vs. 16.0%, p = 0.001), preoperative bowel obstruction (10.3% vs. 32.0%, p = 0.003), laparotomy (56.0% vs. 80.0%, p = 0.02), concomitant resection (2.9% vs. 24.0%, p < 0.001), and postoperative complications (32.0% vs. 56.0%, p = 0.02), and a significantly longer length of hospital stay (median 12 vs. 30 days, p < 0.001). In multivariate analysis, synchronous double cancers (odds ratio 10.2, p = 0.008), preoperative bowel obstruction (odds ratio 4.6, p = 0.01), concomitant resection (odds ratio 5.2, p = 0.03), and postoperative complications of Clavien-Dindo grade ≥ IIIa (odds ratio 4.0, p = 0.03) were identified as independent risk factors for delay in initiating AC.

CONCLUSION

Careful preoperative treatment planning for CRC patients with synchronous double cancers, preoperative bowel obstruction, and concomitant resection, and management for postoperative complication are necessary to avoid delay in initiating AC.

Extent of Lymphadenectomy for Surgical Management of Right-Sided Colon Cancer: The Randomized Phase III RELARC Trial

PURPOSE

Complete mesocolic excision (CME) is being increasingly used for the treatment of right-sided colon cancer, although there is still no strong evidence that CME provides better long-term oncological outcomes than D2 dissection. The controversy is mainly regarding the survival benefit from extended lymph node dissection emphasized by CME.

METHODS

This multicenter, open-label, randomized controlled trial (ClinicalTrials.gov identifier: NCT02619942) was performed across 17 hospitals in China. Patients diagnosed with stage T2-T4aNanyM0 or TanyN + M0 right-sided colon cancer were randomly assigned (1:1) to undergo either CME or D2 dissection during laparoscopic right colectomy. The primary outcome was the 3-year disease-free survival (DFS), and the main secondary outcome was the 3-year overall survival (OS).

RESULTS

Between January 11, 2016, and December 26, 2019, 1,072 patients were randomly assigned (536 patients to CME and 536 patients to D2 dissection). In total, 995 patients (median age 61 years, 59% male) were included in the primary analysis (CME [n = 495] v D2 dissection [n = 500]). No significant differences were found between the groups in 3-year DFS (hazard ratio [HR], 0.74 [95% CI, 0.54 to 1.02]; P = .06; 86.1% in the CME group v 81.9% in the D2 group) or in 3-year OS (HR, 0.70 [95% CI, 0.43 to 1.16]; P = .17; 94.7% in the CME group v 92.6% in the D2 group).

CONCLUSION

This trial failed to find evidence of superior DFS outcome for CME compared with standard D2 lymph node dissection in primary surgical excision of right-sided colon cancer. Standard D2 dissection should be the routine procedure for these patients. CME should only be considered in patients with obvious mesocolic lymph node involvement.

Comparison of D2 vs D3 lymph node dissection for RIght COloN cancer (RICON): study protocol for an international multicenter open-label randomized controlled trial

BACKGROUND

Colon cancer is a global health concern, ranking fifth in both new diagnoses and deaths among tumors worldwide. Surgical intervention remains the primary treatment for localized cases, with a historical evolution marked by a focus on short-term outcomes. While Japan pioneered radical tumor removal with a systematic categorization of lymph nodes (D1, D2, D3), the dissemination of Japanese practices to the West was delayed until 90th of last century. Discrepancies between Japanese D3 dissection and the CME with CVL principle persist, with variations in longitudinal margins and recommended procedures. Non-randomized trials indicate the superiority of D3 over D2, but a consensus is lacking.

METHODS

This prospective, international, multicenter, randomized controlled trial employs a two-arm, parallel-group, open-label design to rigorously compare the 5-year overall survival outcomes between D2 and D3 lymph node dissection in stage II-III right colon cancer. Building on prior studies, the trial aims to address existing knowledge gaps and provide a comprehensive evaluation of the outcomes associated with D3 dissection. The study population comprises patients with right colon cancer, ensuring a focused investigation into the specific context of this disease. The trial design emphasizes its global scope and collaboration across multiple centers, enhancing the generalizability of the findings.

DISCUSSION

This study's primary objective is to elucidate the potential superiority in 5-year overall survival benefits of D3 lymph node dissection compared to the conventional D2 approach in patients with stage II-III right colon cancer. By examining this specific subset of patients, the research aims to contribute valuable insights into optimizing surgical strategies for improved long-term outcomes. The trial's international and multicenter nature enhances its applicability across diverse populations. The outcomes of this study may inform future guidelines and contribute to the ongoing discourse surrounding the standardization of colon cancer surgery, particularly in the context of right colon cancer.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03200834. Registered on June 27, 2017.

Laparoscopic right radical hemicolectomy: Central vascular ligation and complete mesocolon excision vs D3 lymphadenectomy - How I do it?

In colon cancer surgery, ensuring the complete removal of the primary tumor and draining lymph nodes is crucial. Lymphatic drainage in the colon follows the vascular supply, typically progressing from pericolic to paraaortic lymph nodes. While NCCN guidelines recommend the removal of 10-12 lymph nodes for adequate oncological resection, achieving complete oncological resection involves more than just meeting these numerical targets. Various techniques have been developed and studied over time to attain optimal oncological outcomes. A key technique central to this goal is identifying the ileocolic vessels at their origin from the superior mesenteric vessels. Complete excision of the visceral and parietal mesocolon ensures the intact removal of the specimen, while D3 lymphadenectomy targets all draining regional lymph nodes. Although these principles emphasize different aspects, they ultimately converge to achieve the same goal of complete oncological resection. This article aims to simplify the surgical steps that align with the principle of central vascular ligation and mesocolon mobilization while ensuring adequate D3 dissection.

Laparoscopic Dissection of Lymph Node Station 16-Why and How?

BACKGROUND

Dissection of para-aortic lymph nodes (Station 16) provides an important prognosticator for patients with gastrointestinal, colorectal, and hepatobiliary cancers.1-4 For example, a positive Station 16 lymph node has been shown to lead to 2-year survival of 3% in patients with pancreas adenocarcinoma, akin to stage IV disease.5,6 Thereby, Station 16 involvement can help with the risk/benefit stratification of the decision to move forward with radical surgery.7-9 Furthermore, it has been shown for gallbladder cancer that involvement of Station 16 cannot necessarily be predicted from the dissection of the hepatoduodenal ligament lymph nodes only.10,11 TECHNIQUE: With the patient in the French position, a complete Kocherization and a Cattel-Braasch maneuver is performed, allowing for visualization of LN station 16b. Station 16b is the inferior border of the station 16 compartment. The left renal vein (LRV) serves as an important landmark to identify the superior border of the dissection comprised by Stations 16a2 and 16b1. Station 16a2 dissection may be associated with a traction injury of the left renal vein or damage of right renal or suprarenal arteries and is dissected if there are specific concerns regarding involvement.

CONCLUSIONS

While station 16 provides important prognostic information for risk stratification, a strategic and stepwise approach is needed for a safe sampling. This is accomplished by wide mobilization of the duodenum, implementation of thermal fusion to minimize chyle leak, and careful dissection below the left renal vein.

Short-term and Mid-term Outcomes of Indocyanine Green Fluorescence Imaging-Guided Laparoscopic Right-Sided Colectomy: A Propensity Score-Matched Cohort Study

BACKGROUND

With the use of indocyanine green fluorescence imaging, intraoperative lymphatic flow assessment is possible. However, no report has indicated mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy.

OBJECTIVE

To analyze the mid-term outcomes of indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy.

DESIGN

This was a retrospective, multi-institutional study that used propensity score matching.

SETTINGS

We conducted this study within the framework of the Yokohama Clinical Oncology Group in Japan.

PATIENTS

A total of 921 patients who underwent laparoscopic right-sided colectomy with lymph node dissection for colon cancer with clinical stages I to III between January 2009 and December 2020 were included. The patients were divided into 2 groups: 233 patients who underwent the lymphatic flow evaluation (indocyanine green group) and 688 patients who did not undergo lymphatic flow evaluation (non-indocyanine green group).

MAIN OUTCOMES MEASURES

The 3-year relapse-free survival after laparoscopic right-sided colectomy with and without indocyanine green fluorescence imaging were compared.

RESULTS

After propensity score matching, 231 patients were matched in each group. The numbers of dissected central lymph nodes (6 vs 4, p < 0.001), intermediate lymph nodes (7 vs 6, p = 0.03), and the total number of dissected lymph nodes (31 vs 27, p = 0.047) were significantly higher in the indocyanine green group. The median follow-up was 36.9 months. The estimated respective 3-year relapse-free survival and overall survival rates were 88.8% and 94.5% in the indocyanine green group and 89.4% and 94.7% in the non-indocyanine green group ( p = 0.721 and 0.300), respectively, with no difference between the 2 groups.

LIMITATIONS

Retrospective design of the study.

CONCLUSIONS

Indocyanine green fluorescence imaging-guided laparoscopic right-sided colectomy could increase the number of total, intermediate, and central lymph nodes. However, there was no difference in mid-term outcomes. See Video Abstract.

RESULTADOS A CORTO Y MEDIO PLAZO DE LA COLECTOMA LAPAROSCPICA DEL LADO DERECHO GUIADA POR IMGENES DE FLUORESCENCIA CON VERDE DE INDOCIANINA UN ESTUDIO DE COHORTE EMPAREJADO POR PUNTAJE DE PROPENSIN

ANTECEDENTES:Con el uso de imágenes de fluorescencia verde de indocianina, es posible la evaluación del flujo linfático intraoperatorio. Sin embargo, no hay ningún reporte que indique los resultados a medio plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.OBJETIVO:Examinar los resultados a mediano plazo de la colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina.DISEÑO:Estudio multiinstitucional retrospectivo con emparejamiento de puntuación de propensión.CONFIGURACIÓN:Realizado en el marco del Grupo de Oncología Clínica de Yokohama en Japón.PACIENTES:Un total de 921 pacientes sometidos a colectomía laparoscópica del lado derecho con disección de ganglios linfáticos por cáncer de colon con estadio clínico I a III entre enero de 2009 y diciembre de 2020. Los pacientes se dividieron en dos grupos: 233 pacientes sometidos a la evaluación del flujo linfático (grupo con verde de indocianina) y 688 pacientes que no sometidos a la evaluación del flujo linfático (grupo sin verde de indocianina).PRINCIPALES MEDIDAS DE RESULTADOS:Se comparó la supervivencia libre de recaídas a los 3 años después de la colectomía laparoscópica del lado derecho con y sin imágenes de fluorescencia con verde de indocianina.RESULTADOS:Después de emparejar el puntaje de propensión, 231 pacientes fueron emparejados en cada grupo. El número de ganglios linfáticos centrales disecados (6 frente a 4, p < 0,001) y de ganglios linfáticos intermedios (7 frente a 6, p = 0,03) y el número total de ganglios linfáticos disecados (31 frente a 27, p = 0,047) fueron significativamente mayor en el grupo verde de indocianina. La mediana de seguimiento fue de 36,9 meses. Las tasas respectivas estimadas de supervivencia libre de recaídas y supervivencia general a los 3 años fueron del 88,8 % y el 94,5 % en el grupo con verde de indocianina y del 89,4 % y el 94,7 % en el grupo sin verde de indocianina ( p = 0,721 y 0,300), sin diferencias entre los dos grupos.LIMITACIONES:Estudio de diseño retrospectivo.CONCLUSIONES:La colectomía laparoscópica del lado derecho guiada por imágenes de fluorescencia con verde de indocianina puede aumentar el número de ganglios linfáticos totales, intermedios y centrales. Sin embargo, no hubo diferencias en los resultados a medio plazo. (Traducción-Dr. Fidel Ruiz Healy ).

Robotic versus laparoscopic approach for left-sided colon cancer: a nationwide cohort study

AIM

The use of robot-assisted surgery for left-sided colon cancer is increasing in Denmark; however, it is yet to be established if the robotic approach results in improved clinical outcomes compared with the corresponding laparoscopic approach. The aim of this study was to compare the intraoperative and short-term postoperative outcomes of robot-assisted surgery with laparoscopic surgery for left-sided colon cancer at a national level.

METHOD

The study is a nationwide database study based on data from the Danish Colorectal Cancer Group database. Patients from all colorectal centres in Denmark treated with surgery with curative intent in an elective setting with either robotic or laparoscopic left colectomy or sigmoidectomy during the period 2014-2019 were included. To adjust for confounding, propensity score matching (PSM) was performed and the groups were compared for age, sex, body mass index, American Society of Anesthesiologists classification, performance score, year of diagnosis, neoadjuvant chemotherapy, left colectomy or sigmoidectomy, tumour localization, use of stoma or stenting and pathological T (pT) category.

RESULTS

A total of 5532 patients were available for analysis, and after PSM in a ratio of 2:1, 1392 laparoscopic and 696 robotic cases were identified. After matching we found a lower conversion rate and a higher lymph node yield in the robotic group compared with the laparoscopic group (5.8% vs. 11%, p < 0.001 and 27 vs. 24, p < 0.001, respectively). Further, we found a higher proportion of patients with a lymph node yield of 12 or more in the robotic group (97% vs. 94.8%, p = 0.02). Plane of dissection, radicality and pathological disease stages did not differ between the two groups. We found no difference in either overall surgical (13% vs. 11.1%, p = 0.23) or medical (5.6% vs. 6.5%, p = 0.49) postoperative complications and no difference in 30-day (p = 0.369) or 90-day mortality (p = 0.08).

CONCLUSION

Robot-assisted surgery for left-sided colon cancer was associated with a significantly lower conversion rate and a significantly higher lymph node yield than the laparoscopic approach. Postoperative morbidity and mortality were similar in the two groups.

Results of Laparoscopic Surgery and D3 Lymph Node Dissection Combined With Chemotherapy for the Radical Treatment of Advanced-Stage Right Colon Cancer: A Single-Center Observational Study in Vietnam

AIM

To describe the results of laparoscopic surgery and D3 lymph node dissection combined with adjuvant chemotherapy (ACT) for the treatment of advanced-stage right colon cancer (stages II and III).

METHODS

A total of 172 right colon cancer patients (with tumour, node, and metastasis (TNM) stage II and III; mean age of 59.30±14.27 years; 58.1% male, 41.9% female) who had undergone complete mesocolic excision (CME) with D3 lymph node dissection at Nguyen Tri Phuong Hospital, Ho Chi Minh City, Vietnam, were included in this study. They were divided into two groups: group 1 (n=34) without ACT and group 2 (n=138) with ACT. We collected clinical and laboratory data twice (before and after one year of performing laparoscopic surgery). Rates of recurrence and mortality were obtained during a five-year follow-up.

RESULTS

After one year of surgery, the rate of anemia and the increase in serum carcinoembryonic antigen (CEA) levels in group 1 were significantly higher than those in group 2 (p<0.001). After five years of follow-up, the recurrence rate was 11.6% (that of group 1 was 41.2%, which is higher than that of group 2, i.e., 4.3%; p<0.001), and the mortality rate was 8.7% (that of group 1 was 32.4%, which is higher than that of group 2, i.e., 2.9%; p<0.001). Preoperative serum CEA levels were predictive of recurrence and mortality, with an area under the curve (AUC) of 0.729 and 0.805, respectively (p<0.001).

CONCLUSIONS

Laparoscopic CME surgery and D3 lymph node dissection combined with ACT reduced the five-year recurrence and mortality rates for advanced-stage right colon cancer patients.

The concept of developmental anatomy: the greater omentum should be resected in right-sided colon cancer?

BACKGROUND

The greater omentum is derived from the foregut, and the right hemicolon is derived from the midgut based on developmental anatomy. This study aimed to investigate whether the greater omentum should be resected in laparoscopic complete mesocolic excision based on developmental anatomy for right-sided colon cancer.

METHODS

A total of 183 consecutive patients with right-sided colon cancer were recruited in this study between February 2020 and July 2022. Ninety-eight patients underwent standard laparoscopic complete mesocolic excision surgery (CME group). The presence of isolated tumor cells and micrometastases was detected in resected greater omentum by the HE staining and immunohistochemistry analysis. Based on developmental anatomy, laparoscopic CME surgery with greater omentum preservation (DACME group) was proposed and performed on 85 right-sided colon cancer patients. To overcome selection bias, we performed a 1:1 match between two groups using four variables: age, sex, BMI, and ASA scores.

RESULTS

No isolated tumor cells and micrometastases were found in the resected greater omentum specimen in the CME group. After the propensity score, 81 pairs were balanced and analyzed. Patients in the DACME group showed shorter operative time (194.9 ± 16.4 min vs.201.5 ± 11.5 min, p = 0.002), less blood loss (23.5 ± 24.7 ml vs.33.6 ± 26.3 ml, p = 0.013), and the shorter hospital stays (9.6 ± 1.7 days vs.10.3 ± 2.0 days, p = 0.010) compared with patients in the CME group. In addition, patients in the DACME group had a lower incidence of postoperative complications (4.9% vs.14.8%, p = 0.035) than patients in the CME group.

CONCLUSION

The greater omentum should be preserved during right-sided colon cancer surgery, laparoscopic CME surgery based on developmental anatomy is technically safe and feasible for right-sided colon cancer.

Long-term oncologic outcome of D3 lymph node dissection for clinical stage 2/3 right-sided colon cancer

PURPOSE

To investigate oncologic outcomes including overall survival and disease-free survival depending on the extent of lymphadenectomy (D3 versus D2) by comparing D3 and D2 lymphadenectomy in patients with clinical stage 2/3 right colon cancer.

METHODS

Consecutive series of patients who underwent radical resection for right colon cancer at our three hospitals between January 2015 and June 2018 were retrospectively analyzed. Study cohorts were divided into two groups: D3 group and D2 group. Oncologic, pathologic, and perioperative outcomes of the two groups were compared.

RESULTS

A total of 295 patients (167 in the D2 group and 128 in the D3 group) were included in this study. Patients' characteristics showed no significant difference between the two groups. The median number of harvested lymph nodes was significantly higher in the D3 group than in the D2 group. The rate of complications was not significantly different between the two groups except for chyle leakage, which was more frequent in the D3 group. Five-year disease-free survival was 90.2% (95% CI: 84.8-95.9%) in the D3 group, which was significantly (p = 0.028) higher than that (80.5%, 95% CI: 74-87.5%) in the D2 group. There was no significant difference in overall survival between the two groups.

CONCLUSION

Our results indicate that D3 lymphadenectomy is associated with more favorable 5-year disease-free survival than D2 lymphadenectomy for patients with stage 2/3 right-sided colon cancer. D3 lymphadenectomy might improve oncologic outcomes in consideration of the recurrence rate.

D3 lymph node dissection improves the survival outcome in patients with pT2 colorectal cancer

BACKGROUND

The extent of lymphadenectomy in patients with pT2 colorectal cancer (CRC) remains controversial. This study aimed to elucidate the effects of D3 and D2 lymph node dissection (LND) on survival in patients diagnosed with pT2 CRC.

METHODS

This was a retrospective cohort study from a high-volume cancer center in Japan. From April 2007 to December 2020, 6273 patients with primary CRC were included in the study; among these, 616 patients diagnosed with pT2 CRC underwent radical colorectal resection. Propensity score matching (PSM) was applied to balance potential confounding factors, and a total of 104 matched pairs were extracted from the entire cohort. Independent risk factors associated with prognosis were determined by Cox regression analysis. The main outcome measures were overall survival (OS) and cancer-specific survival (CSS).

RESULTS

Before PSM, there was a statistically significant difference across the cohort in OS and CSS (p = 0.000 and 0.013) between D3 and D2 LND groups; the estimated hazard ratio (HR) was 2.2 (95% confidence interval (CI), 1.1-4.4, p = 0.031) for OS in the D3 LND and 4.4 (95% CI, 1.7 to 11, p = 0.0027) for CSS (p = 0.013). There was also a significant difference (p = 0.024) in OS between the D3 and D2 LND groups in the matched cohort, with an estimated HR for OS of 3.3 (95% CI, 1.2 to 9.1, p = 0.024) and an estimated HR for CSS of 7.2 (95% CI, 1.6 to 33, p = 0.011).

CONCLUSIONS

D3 LND had a significant survival advantage in the treatment of pT2 CRC. The results of this study provide a theoretical basis for the application of D3 LND in radical surgery for preoperative T2 CRC.

Prognostic Impact of Main Lymph Node Metastasis in Patients with Colon Cancer

BACKGROUND

Although extended lymph node dissection during colon cancer surgery is recommended in both Western and Eastern countries, the perception and clinical significance of main lymph node metastasis (MLNM) remains controversial.

METHODS

In total, 1557 patients with colon cancer who underwent curative resection with D3 dissection were retrospectively analyzed. Clinicopathological factors associated with MLNM were analyzed. Kaplan-Meier survival analysis and log-rank tests were used to compare the prognosis between the MLNM and non-MLNM groups.

RESULTS

Multivariate analysis showed that overall survival (OS) [hazard ratio, 2.117 (0.939-4.774), p = 0.071] and recurrence-free survival (RFS) [hazard ratio, 2.183 (1.182-4.031), p = 0.013] were affected by the MLNM status independent of the TNM stage. Survival analysis demonstrated that among patients with stage III disease, the OS and RFS rates were significantly different between patients with and without MLNM (OS: p = 0.0147, RFS: p = 0.0001). However, the OS and RFS rates were not significantly different between patients who had stage III disease with MLNM and patients who had stage IV disease (OS: p = 0.5901, RFS: p = 0.9610).

CONCLUSIONS

MLNM is an independent prognostic factor for patients with colon cancer. The addition of the MLNM status to the current TNM classification may enhance the prognostic value of the TNM staging system and the clinical efficacy of adjuvant therapy in patients with colon cancer.

Molecular testing to deliver personalized chemotherapy recommendations: risking over and undertreatment

BACKGROUND

In the adjuvant setting of cancer treatment, de-escalation strategies have the goal of omitting or minimizing treatment in patients, without compromising outcomes. Historically, eligibility for adjuvant treatment solely relied on the patient's clinical and tumor's pathological characteristics. At the turn of the century, based on new biological understanding, molecular-based strategies were tested and sometimes implemented.

MAIN BODY

However, we illustrate how molecularly based de-escalation strategies may paradoxically lead to overtreatment. This may happen when the novel approach is tested in lieu of standard management and may not yield the same results when being implemented in addition to usual practice. In the DYNAMIC trial, adjuvant chemotherapy decision in stage II colon cancer was compared between a circulating tumor DNA (ctDNA)-based approach and the standard care. We show this may result in more patients receiving oxaliplatin-based chemotherapy and may expose a similar proportion of patients to chemotherapy if the novel strategy is implemented in addition to usual practice. The other potential risk is undertreatment. We provide an illustration of early breast cancer, where the decision of adjuvant chemotherapy based on the gene expression signature MammaPrint may lead to inferior outcomes as compared with the clinico-pathologic strategy. This may also happen when non-inferiority designs have large margins. Among solutions, it should be acknowledged that clinico-pathological features, like T4 in colon cancer, may not be abandoned and replaced by novel strategies in real-life practice. Therefore, novel strategies should be tested in addition to standard of care, and not in lieu of. Second, de-escalation trials should focus on the settings where the standard of care has a widespread agreement. This would avoid the risk of testing non-inferiority against an ineffective therapy, which guarantees successes without providing informative data.

CONCLUSION

Simply because a molecular test is rational does not mean it can improve patient outcomes. Here, we highlight how molecular test-based strategies may result in either overtreatment or undertreatment. In the rapidly evolving field of medicine, where technological advances may be transformative, our piece highlights scientific pitfalls to be aware of when considering running such trials or before implementing novel strategies in daily practice.

Real impact of oxaliplatin in adjuvant chemotherapy for patients with stage III colon cancer based on the Multi-Institutional Registry of Large Bowel Cancer in Japan

Although fluoropyrimidine plus oxaliplatin is the standard of care for stage III colon cancer, fluoropyrimidine alone is also recommended for stage III patients in Japanese and other practice guidelines. We assessed efficacy of adjuvant fluoropyrimidine with or without oxaliplatin across a population of patients with stage III colon cancer in the Multi-Institutional Registry of Large Bowel Cancer in Japan. From the registry, we analyzed 6,834 stage III colorectal cancer patients. Approximately 70% of colorectal cancer patients received some form of chemotherapy. Of these, we analyzed those who received adjuvant chemotherapy between 2008 and 2011. Based on the TNM classification, the 5-year overall survival rates of colon and rectal cancer after the covariate adjustment by regimens of adjuvant chemotherapy were 95.7% with fluoropyrimidines and 90.6% with oxaliplatin-combined therapy at stage IIIA (Stratified log-rank P < 0.001), 86.5% and 80.8% at stage IIIB (P < 0.001), and 72.1% and 70.7% at stage IIIC (P < 0.001), respectively. Oxaliplatin did not enhance efficacy with regard to relapse-free survival as well as overall survival. Adjuvant fluoropyrimidine monotherapy and fluoropyrimidine plus oxaliplatin show comparable efficacy benefits for the treatment of stage III of Japanese colon cancer patients. This supports the use of fluoropyrimidine alone as a standard option for this patient group in Japan.

Computer-Assisted Differentiation between Colon-Mesocolon and Retroperitoneum Using Hyperspectral Imaging (HSI) Technology

Complete mesocolic excision (CME), which involves the adequate resection of the tumor-bearing colonic segment with “en bloc” removal of its mesocolon along embryological fascial planes is associated with superior oncological outcomes. However, CME presents a higher complication rate compared to non-CME resections due to a higher risk of vascular injury. Hyperspectral imaging (HSI) is a contrast-free optical imaging technology, which facilitates the quantitative imaging of physiological tissue parameters and the visualization of anatomical structures. This study evaluates the accuracy of HSI combined with deep learning (DL) to differentiate the colon and its mesenteric tissue from retroperitoneal tissue. In an animal study including 20 pig models, intraoperative hyperspectral images of the sigmoid colon, sigmoid mesentery, and retroperitoneum were recorded. A convolutional neural network (CNN) was trained to distinguish the two tissue classes using HSI data, validated with a leave-one-out cross-validation process. The overall recognition sensitivity of the tissues to be preserved (retroperitoneum) and the tissues to be resected (colon and mesentery) was 79.0 ± 21.0% and 86.0 ± 16.0%, respectively. Automatic classification based on HSI and CNNs is a promising tool to automatically, non-invasively, and objectively differentiate the colon and its mesentery from retroperitoneal tissue.

Risk of Local Recurrence After Complete Mesocolic Excision for Right-Sided Colon Cancer: Post-Hoc Sensitivity Analysis of a Population-Based Study

BACKGROUND

A causal treatment effect of complete mesocolic excision for right-sided colon cancer on the risk of recurrence has been shown, but it is still unclear whether this is caused solely by a risk reduction of local recurrence.

OBJECTIVE

The goal of this study was to assess to what extent complete mesocolic excision contributes to the risk of local recurrence.

DESIGN

This study was a posthoc analyses of data from a population-based cohort. Inverse probability of treatment weighting and competing risk analyses were used to estimate the possible causal effects of complete mesocolic excision.

SETTING

Data were collected from the 4 public colorectal cancer centers in the Capital Region of Denmark.

PATIENTS

Patients undergoing elective colon resections for right-sided colon cancer without distant metastases during the period 2010-2013 were included. One center performed complete mesocolic excision and the remaining 3 centers performed conventional resections.

MAIN OUTCOME MEASURES

The primary outcome was the cumulative incidence of solely local recurrence 5.2 years after surgery. Secondary outcomes were solely distant recurrence and both local and distant recurrence diagnosed within 180 days.

RESULTS

A total of 807 patients were included with 186 undergoing complete mesocolic excision and 621 conventional resections. The 5.2-year cumulative incidence of a solely local recurrence was 3.7% (95% CI, 0.5-6.1) after complete mesocolic excision compared with 7.0% (5.0-8.9) in the control group, and the absolute risk reduction of complete mesocolic excision was 3.7% (2.5-7.1; p = 0.035). The absolute risk reduction on local and distant recurrence was 3.4% (1.3-5.6; p = 0.002) and on solely distant recurrence was 3.1% (0.0-6.2; p = 0.052).

LIMITATIONS

The recurrence risk after conventional resection might be underestimated by the use of inappropriate modalities to diagnose local recurrence for some patients and the shorter duration in this group.

CONCLUSION

This study shows a causal treatment effect of complete mesocolic excision on the risk of a solely local recurrence and of distant recurrence with or without local recurrence. See Video Abstract at http://links.lww.com/DCR/B832 .RIESGO DE RECURRENCIA LOCAL DESPUÉS DE LA ESCISIÓN MESOCÓLICA COMPLETA PARA EL CÁNCER DE COLON DEL LADO DERECHO: ANÁLISIS DE SENSIBILIDAD POST-HOC DE UN ESTUDIO POBLACIONALANTECEDENTES:Se ha demostrado un efecto del tratamiento causal de la escisión mesocólica completa para el cáncer de colon del lado derecho sobre el riesgo de recurrencia, pero aún no está claro si esto se debe únicamente a una reducción del riesgo de recurrencia local.OBJETIVO:Evaluar en qué medida la escisión mesocólica completa se atribuye al riesgo de recurrencia local.DISEÑO:Análisis posthoc de datos de una cohorte poblacional. Se utilizaron análisis de probabilidad inversa de ponderación del tratamiento y de riesgo competitivo para estimar los posibles efectos causales de la escisión mesocólica completa.AJUSTE:Datos de los cuatro centros públicos de cáncer colorrectal en la Región Capital de Dinamarca.PACIENTES:Pacientes sometidos a resecciones de colon electivas por cáncer de colon derecho sin metástasis a distancia durante el período 2010-2013. Un centro realizó escisión mesocólica completa, el resto resecciones convencionales.PRINCIPALES MEDIDAS DE RESULTADO:El resultado primario fue la incidencia acumulada de la recidiva local únicamente, 5,2 años después de la cirugía. Los resultados secundarios fueron únicamente la recidiva a distancia y ambas,la recidiva local y a distancia diagnosticada dentro de los 180 días.RESULTADOS:Se incluyeron un total de 807 pacientes, 186 sometidos a escisión mesocólica completa y 621 resecciones convencionales. La incidencia acumulada de 5,2 años de una recidiva únicamente local fue del 3,7% (IC del 95%: 0,5 a 6,1) después de la escisión mesocólica completa en comparación con el 7,0% (5,0 a 8,9) en el grupo de control, y la reducción del riesgo absoluto de la escisión mesocólica completa fue del 3,7% (2,5-7,1; p = 0,035). La reducción del riesgo absoluto de recidiva local y distante fue del 3,4% (1,3-5,6; p = 0,0019) y de recidiva únicamente a distancia 3,1% (0,0-6,2; p = 0,052).LIMITANTES:El riesgo de recurrencia después de la resección convencional podría subestimarse por el uso de modalidades inapropiadas para el diagnostico de la recurrencia local en algunos pacientes y la duración más corta en este grupo.CONCLUSIÓN:Este estudio muestra un efecto del tratamiento causal de la escisión mesocólica completa sobre el riesgo de una recidiva únicamente local y de recidiva a distancia con o sin recidiva local. Consulte Video Resumen en http://links.lww.com/DCR/B832 . (Traducción-Dr. Mauricio Santamaria ).

Is increasing nodal count associated with improved recurrence-free and overall survival following standard right hemicolectomy for colon cancer?

BACKGROUND AND OBJECTIVES

Increasing lymph node harvest for right-sided colon cancer is associated with improved overall survival (OS), but most relevant studies failed to report the extent of resection. We examined the association between increasing lymph node count with standard right hemicolectomy according to nodal status and prognostic outcomes in right-sided tumors.

METHODS

Retrospective analysis of prospectively collected clinical data from patients with proximal colonic adenocarcinomas (n = 1390) following right hemicolectomy. Associations between lymph node counts (0-12 vs. 13-15, 16-20, and >20) and recurrence-free survival (RFS) and OS were examined using multivariate Cox modeling adjusted for confounders.

RESULTS

We found no association between increasing nodal count and RFS, regardless of nodal status. In the absence of nodal metastases, increasing nodal count (16-20 and >20 vs. 0-12 nodes) was associated with 57% (95% confidence interval [CI]: 0.21-0.89) and 52% (95% CI: 0.24-0.95) improved OS, respectively. In the presence of nodal metastases, increasing nodal count was not associated with OS. Adjuvant chemotherapy did not modify this effect.

CONCLUSION

Increasing nodal count (>15 nodes) with right hemicolectomy was not associated with improved RFS. Improved OS was only found for node-negative tumors, casting some doubt on the benefits of resecting more lymph nodes in the presence of nodal metastases.

Risk factors of central area lymph nodes metastasis for guiding optimal right colon cancer surgery: A retrospective multicenter study.. [DOI: 10.21203/rs.3.rs-1991182/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

Background: D3 or CME lymphadenectomy for right colon cancer (RCC) with lymph nodes metastasis (LNM) is strongly recommended but the anatomical landmark remains controversial. Central LNM predicted poor prognosis in RCC and determined the extent of lymphadenectomy. Methods: Data for 1712 RCC patients treated with D3/CME lymphadenectomy were reviewed. These patients had been treated in 9 centers. A total of 1023 RCC patients were enrolled in the derivation cohort while 689 patients were enrolled in the validation cohort. Results: The overall central LNM incidence was 12.58% (215/1712). In the derivation cohort, univariate and multivariate cox regression analyses revealed that preoperative N staging based on CT scan (OR=7.85, 95% CI, 4.53-14.51, p<0.001), tumor differentiation (OR=0.53, 95% CI, 0.33-0.86, p=0.01) and intraoperative view of tumor movability (OR=0.53, 95% CI, 0.33-0.86, p=0.02) were significant independent factors. Areas under receiver-operating characteristic curves (AUC) for assessing central LNM in the derivation and validation cohorts were 0.802 and 0.750, respectively. The risk-scoring system for patients with RCC was also established. A score of 0 points was the optimal cut-off value for central LNM. Compared to patients in the low-risk group, patients in the high-risk group exhibited worse overall survival outcomes (p<0.001).Conclusions: The established model can be used for preoperative assessment of the risk of central LNM in RCC patients, and for determining the landmark for D3/CME lymphadenectomy, therefore might contribute to decreased therapeutic complications and improved clinical outcomes.

Outcomes of right-sided and left-sided colon cancer after curative resection

The right and left side of the colon derived from the midgut and hindgut, respectively. Previous studies have reported different characteristics of right-sided colon cancer (RCC) and left-sided colon cancer (LCC), but oncological outcomes remain unclear. This study compared the outcomes of RCC and LCC. This retrospective study included 1017 patients who received curative colectomy for stage I-III colon cancer at a single institute between August 2008 and December 2019. Overall survival (OS) and time to recurrence (TTR) were analyzed as outcome measurements. No significant difference in the OS or TTR of patients with RCC and LCC were observed. In subgroup analysis, RCC was associated with shorter TTR than LCC in stage II colon cancer (HR 2.36, 95% confidence interval 1.24–4.48, p < 0.01). Multivariate analysis demonstrated that right sidedness, R1 resection, low body mass index (BMI) and adjuvant chemotherapy were independent factors for poor prognosis for stage II colon cancer. Low BMI, perineural invasion, higher T stage and N2 stage were independent factors for poor prognosis for stage III colon cancer. The results were confirmed by multivariate analysis after propensity score matching. Our study revealed that RCC was an independent risk factor for recurrence in stage II colon cancer.

The Mesentery in Complete Mesocolic Excision

The following article summarizes technical aspects of how to operate in the mesentery during complete mesocolic excision (CME). Increasingly, CME is being adopted and as such it is important to establish the anatomical basis of the techniques involved. This review thus serves to provide that foundation and explains the surgical techniques built on it.

Pattern of recurrence and survival after D2 right colectomy for cancer: is there place for a routine more extended lymphadenectomy?

BACKGROUND

Conventional Right Colectomy with D2 lymphadenectomy (RC-D2) currently represent the most common surgical treatment of right-sided colon cancer (RCC). However, whether it should be still considered a standard of care, or replaced by a routine more extended D3 lymphadenectomy remains unclear. In the present study, we aim to critically review the patterns of relapse and the survival outcomes obtained from our 11-year experience of RC-D2.

METHODS

Clinical data of 489 patients who underwent RC-D2 for RCC at two centres, from January 2009 to January 2020, were retrospectively reviewed. Patients with synchronous distant metastases and/or widespread nodal involvement at diagnosis were excluded. Post-operative clinical-pathological characteristics and survival outcomes were evaluated including the pattern of disease relapse.

RESULTS

We enrolled a total of 400 patients with information follow-up. Postoperative morbidity was 14%. The median follow-up was 62 months. Cancer recurrence was observed in 55 patients (13.8%). Among them, 40 patients (72.7%) developed systemic metastases, and lymph-node involvement was found in 7 cases (12.8%). None developed isolated central lymph-node metastasis (CLM), in the D3 site. The estimated 3- and 5-year relapse-free survival were 86.1% and 84.4%, respectively. The estimated 3- and 5-year cancer-specific OS were 94.5% and 92.2%, respectively.

CONCLUSIONS

The absence of isolated CLM, as well as the cancer-specific OS reported in our series, support the routine use of RC-D2 for RCC. However, D3 lymphadenectomy may be recommended in selected patients, such as those with pre-operatively known CLM, or with lymph-node metastases close to the origin of the ileocolic vessels.

The Conventional Technique Versus the No-touch Isolation Technique for Primary Tumor Resection in Patients With Colon Cancer (JCOG1006): A Multicenter, Open-label, Randomized, Phase III Trial

OBJECTIVE

This phase III trial evaluated whether the no touch was superior to the conventional in patients with cT3/T4 colon cancer.

BACKGROUND

No touch involves ligating blood vessels that feed the primary tumor to limit cancer cell spreading. However, previous studies did not confirm the efficacy of the no touch.

METHODS

This open-label, randomized, phase III trial was conducted at 30 Japanese centers. The eligibility criteria were histologically proven colon cancer; clinical classification of T3-4, N0-2, andM0; and patients aged 20 to 80years. Patients were randomized (1:1) to undergo open surgery with conventional or the no touch. Patients with pathological stage III disease received adjuvant capecitabine chemotherapy. The primary endpoint was disease-free survival (DFS) according to the intention-to-treat principle.

RESULTS

Between January 2011 and November 2015, 853 patients were randomized to the conventional group (427 patients) or the no touch group (426 patients). The 3-year DFS were 77.3% [95% confidence interval (CI) 73.1%-81.0%] and 76.2% (95% CI 71.9%-80.0%) in the conventional and no touch groups, respectively. The superiority of no touch was not confirmed: hazard ratio for DFS = 1.029 (95% CI 0.800- 1.324; 1-sided P = 0.59). Operative morbidity was observed in 31 of 427 conventional patients (7%) and 26 of 426 no touch patients (6%). All grade adverse events were similar between the conventional and no touch groups. No in-hospital mortality occurred in either group.

CONCLUSION

The present study failed to confirm the superiority of the no touch.

ICG-Guided Lymphadenectomy during Surgery for Colon and Rectal Cancer-Interim Analysis of the GREENLIGHT Trial

Lymphadenectomy is crucial for an optimal oncologic resection of colon and rectal cancers. However, without a direct visualization, an aberrant route of lymph node (LN) diffusion might remain unresected. Indocyanine-green (ICG) lymphatic mapping permits a real-time LNs visualization. We designed the GREENLIGHT trial to explore in 100 patients undergoing robotic colorectal resection the clinical significance of a D3 ICG-guided lymphadenectomy. The primary endpoint was the number of patients in whom ICG changed the extent of lymphadenectomy. We report herein the interim analysis on the first 70 patients. After endoscopic ICG injection 24 h (n = 49) or 72 h (n = 21) ahead, 19, 20, and 31 patients underwent right colectomy, left colectomy, and anterior rectal resection. The extent of lymphadenectomy changed in 35 (50%) patients, mostly (29 (41.4%)) for the identification of LNs (median two) outside the standard draining basin. Identification of such LNs was less frequent in rectal tumors that had undergone chemoradiotherapy (26.3%) (p > 0.05). A non-significant correlation between time-to-ICG injection and identification of aberrant LNs was observed (48.9% at 24 h vs. 23.8% at 72 h). The presence of LN metastases did not affect a proper fluorescent mapping. These data indicate that ICG lymphatic mapping provides relevant information in 50% of patients, thus increasing the accuracy of potentially curative resections.

D3 Versus D2 Lymphadenectomy in Right Hemicolectomy: A Systematic Review and Meta-analysis

PURPOSE

D3 lymphadenectomy for right colon cancer improves oncological outcomes. This meta-analysis aimed to compare operation data, histopathological characteristics, perioperative conditions, and long-term survival after D3 and D2 lymphadenectomy in right hemicolectomy.

METHODS

We searched PubMed, Embase, and the Cochrane Library for relevant articles (up to March 31, 2020). Random-effects and fixed-effects meta-analysis models were used. Review Manager (RevMan) version 5.3 and Stata version 15.1 were used for pooled estimates.

RESULTS

After screening 714 articles, 7 articles with a total of 1368 patients were eligible for inclusion. Compared with D2, D3 lymphadenectomy improves results in terms of blood loss (weighted mean difference [WMD] = -20.63, 95% confidence interval [CI] -28.19 to -13.16, P < .01), harvested lymph nodes (WMD = 8.86, 95% CI 7.74 to 9.98, P < .01), 3-year overall survival (OS) (hazard ratio [HR] = 2.03, 95% CI 1.20 to 3.43, P < .01), 5-year OS (HR = 2.22, 95% CI 1.15 to 4.30, P = .02), and 5-year disease-free survival (DFS) (HR = 2.16, 95% CI 1.19 to 3.90, P = .01). There was no significant difference regarding operation time, anastomosis leakage, wound infection, overall morbidity, postoperative hospital stay, mortality, length of dissected colon, and 3-year DFS (P >= .05).

CONCLUSIONS

It is suggested in this review that D3 lymphadenectomy is superior to D2 lymphadenectomy in terms of blood loss, harvested lymph nodes, 3-year OS, 5-year OS, and 5-year DFS. The conclusion must be drawn with caution due to the limited number of included studies. Further RCTs are needed for stronger evidence.

Exploring Central Vascular Anatomy With Axial Computed Tomography During Surgery for Sigmoid Colon and Rectal Cancer: New Insights Into the Anatomical Relationship Between the Inferior Mesenteric Artery and the Duodenum

Background: In some individuals, the inferior mesenteric artery (IMA) originates from the aorta above the lower edge of the duodenum. This anatomical feature has rarely been reported but may be important in guiding central vascular ligation and lymph node dissection in colorectal surgery. This retrospective study aimed to explore the anatomical relationship between the IMA and the duodenum and evaluate its potential impact on the efficacy of D3 lymph node dissection.

Methods: A total of 439 patients undergoing laparoscopic colorectal surgery at the Department of General Surgery, Qilu Hospital of Shandong University, were retrospectively enrolled. Clinical data from axial computed tomography (CT) scans were collected and analysed.

Results: In 27.69% of patients, the IMA originated at or above the lower edge of the duodenum (median distance: −8 mm). These patients were characterised by a shorter superior mesenteric artery to aortic bifurcation distance, a superiorly located IMA origin, and a greater distance between the IMA and both the left colic artery and the inferior mesenteric vein. The number of harvested lymph nodes was not significantly associated with the distance between the IMA and the duodenum (P = 0.858).

Conclusions: Preoperative axial CT scans can provide a great deal of information regarding central vascular anatomy in the context of sigmoid colon and rectal cancer surgery. Nearly one-third of patients have the IMA originating at or above the duodenum. Whether this anatomical feature affects D3 lymph node dissection warrants further investigation.

Survival outcomes for right-versus left-sided colon cancer and rectal cancer in England: A propensity-score matched population-based cohort study

INTRODUCTION

The aim of this study was to evaluate 5-year overall survival (OS) in patients operated on for potentially curable right versus left-sided colon cancer and rectal cancer in England.

MATERIALS AND METHODS

A retrospective propensity-score matched population-based cohort study was performed using data from English Hospital Episode Statistics, Office for National Statistics and National Bowel Cancer Audit dataset. Patients ≥18 who underwent elective resection for right-colon, left-colon, or rectal cancer between 2000 and 2015 were included. Patients were matched using propensity scores with the dependant variable being site of primary tumour (right-colon, left-colon, or rectum) and independent variables age, Charlson comorbidity index, operation year and Duke's stage. The primary outcome was 5-year overall survival (OS).

RESULTS

A total of 167,606 patients were included. Following propensity-score matching 26,662 patients remained in each group (right-colon, left-colon, and rectum). 5-year OS was significantly worse for patients with Duke's A-C right-sided primaries compared to left-sided and rectal cancers in the unmatched (58.8% vs 66.7% vs 70.0% p=<0.001) and matched cohorts (62.6%, 66.8%, 65.8% p=<0.001). Superior OS for patients with left-sided colon cancer was demonstrated across all stages (Duke's A HR 0.845, p = 0.003; Duke's B HR 0.947, p = 0.045; Duke's C HR 0.783, p < 0.0001). Secondary analysis demonstrated equivalent OS between study groups when ≥22 lymph nodes were harvested.

CONCLUSION

There is a significant difference in survival between comparable patients with right and left sided colon cancers in England. The quality and/or extent of mesenteric resection may be of particular importance in right-sided colon cancer.

Robotic versus laparoscopic right colectomy for colon cancer: a nationwide cohort study

PURPOSE

On a national level, the minimally invasive approach is widely adopted in Denmark. The adoption of robotic colorectal surgery is increasing; however, the advantage of a robotic approach in right colectomy is still uncertain. The purpose of this study was to compare robotic right colectomy with laparoscopic right colectomy on a national level.

METHODS

This was a nationwide database study based on data from the Danish Colorectal Cancer Group database. Patients from all colorectal centers in Denmark in the period 2014-2018 treated with curative intend in an elective setting with either robotic or laparoscopic right colectomy were identified. Propensity score matching was performed to adjust for confounding, and the groups were compared on demographics, disease characteristics, operative data, and postoperative and pathology outcomes. Reporting was done in accordance with the STROBE statement.

RESULTS

In total, 4002 patients were available for analysis. Propensity score matching in ratio 2:1 identified 718 laparoscopic and 359 robotic cases. After matching, we found a higher lymph node yield in the robotic group compared to the laparoscopic group, (32.5 vs. 28.4, P < 0.001), while radicality, plane of dissection, and pathological disease stages showed no differences. There were no statistical differences in morbidity and mortality. Intracorporeal anastomosis (23.7% vs. 4.5%, P < 0.001) was more commonly performed with a robotic approach.

CONCLUSIONS

Robotic approach was associated with a significant higher lymph node yield and with similar postoperative morbidity compared to a laparoscopic approach for right colectomy.

Brazilian society of surgical oncology: Guidelines for the surgical treatment of mid-low rectal cancer

BACKGROUND

Colorectal cancer (CRC) is the third leading cause of cancer in North America, Western Europe, and Brazil, and represents an important public health problem. It is estimated that approximately 30% of all the CRC cases correspond to tumors located in the rectum, requiring complex multidisciplinary treatment. In an effort to provide surgeons who treat rectal cancer with the most current information based on the best evidence in the literature, the Brazilian Society of Surgical Oncology (SBCO) has produced the present guidelines for rectal cancer treatment that is focused on the main topics related to daily clinical practice.

OBJECTIVES

The SBCO developed the present guidelines to provide recommendations on the main topics related to the treatment of mid-low rectal cancer based on current scientific evidence.

METHODS

Between May and June 2021, 11 experts in CRC surgery met to develop the guidelines for the treatment of mid-low rectal cancer. A total of 22 relevant topics were disseminated among the participants. The methodological quality of a final list with 221 sources was evaluated, all the evidence was examined and revised, and the treatment guideline was formulated by the 11-expert committee. To reach a final consensus, all the topics were reviewed via a videoconference meeting that was attended by all 11 of the experts.

RESULTS

The prepared guidelines contained 22 topics considered to be highly relevant in the treatment of mid-low rectal cancer, covering subjects related to the tests required for staging, surgical technique-related aspects, recommended measures to reduce surgical complications, neoadjuvant strategies, and nonoperative treatments. In addition, a checklist was proposed to summarize the important information and offer an updated tool to assist surgeons who treat rectal cancer provide the best care to their patients.

CONCLUSION

These guidelines summarize concisely the recommendations based on the most current scientific evidence on the most relevant aspects of the treatment of mid-low rectal cancer and are a practical guide that can help surgeons who treat rectal cancer make the best therapeutic decision.

Recurrence after complete mesocolic excision for right-sided colon cancer: post hoc sensitivity analyses-early recurrence, surgery by specialist and dissection in the mesocolic plane

AIM

The aim was to investigate whether the previously reported causal treatment effect of complete mesocolic excision on the risk of recurrence was biased by inclusion of patients with potentially undiagnosed disseminated disease at the time of surgery, by non-specialist surgery, or caused by mesocolic plane dissection.

METHOD

A population of 1069 patients, 813 undergoing conventional resection and 256 complete mesocolic excision for colon cancer during the period 2008-2013, was stepwise reduced in the following order by excluding patients with recurrence diagnosed within 6 months of the resection, having surgery performed by a non-specialist without supervision, and specimens assessed as not being mesocolic plane dissection. The primary outcome measure was risk of recurrence after 5.2 years using competing risk analyses.

RESULTS

The absolute risk reduction of complete mesocolic excision was 6.0% (95% CI 1.8-10.2; P = 0.0049) after excluding patients with recurrence within 6 months of resection, 6.1% (95% CI 1.9-10.4; P = 0.0045) after excluding non-specialist surgery, and 7.5% (95% CI 2.9-12.0; P = 0.0013) after the exclusion of patients whose specimens were assessed as dissections not being performed in the mesocolic plane.

CONCLUSION

The absolute risk reduction of recurrence after complete mesocolic excision for right-sided colon cancer in our previous study was not biased by potentially undiagnosed disseminated disease at the time of surgery or non-specialist surgery, and was not solely caused by dissection in the mesocolic plane. Central vascular dissection with central lymphadenectomy seems a major factor for better oncological results.

Complete mesocolic excision versus conventional surgery for colon cancer: A systematic review and meta-analysis

AIM

Complete mesocolic excision (CME) lacks consistent data advocating operative superiority compared to conventional surgery for colon cancer. We performed a systematic review and meta-analysis, analysing population characteristics and perioperative, pathological and oncological outcomes.

METHODS

D3 extended lymphadenectomy dissection was considered comparable to CME, and D2 and D1 dissection to be comparable to conventional surgery. Outcomes reviewed included lymph node yield, R1 resection, overall complications, overall survival and disease-free survival.

RESULTS

In all, 3039 citations were identified; 148 studies underwent full-text reviews and 31 matched inclusion criteria: total cohort 26 640 patients (13 830 CME/D3 vs. 12 810 conventional). Overall 3- and 5-year survival was higher in the CME/D3 group compared with conventional surgery: relative risk (RR) 0.69 (95% CI 0.51-0.93, P = 0.016) and RR 0.78 (95% CI 0.64-0.95, P = 0.011) respectively. Five-year disease-free survival also demonstrated CME/D3 superiority (RR 0.67, 95% CI 0.52-0.86, P < 0.001), with similar findings at 1 and 3 years. There were no statistically significant differences between the CME/D3 and conventional group in overall complications (RR 1.06, 95% CI 0.97-1.14, P = 0.483) or anastomotic leak (RR 1.02, 95% CI 0.81-1.29, P = 0.647).

CONCLUSIONS

Meta-analysis suggests CME/D3 may have a better overall and disease-free survival compared to conventional surgery, with no difference in perioperative complications. Quality of evidence regarding survival is low, and randomized control trials are required to strengthen the evidence base.

Laparoscopic complete mesocolic excision versus conventional resection for right-sided colon cancer: a propensity score matching analysis of short-term outcomes

BACKGROUND

Complete mesocolic excision (CME) for right-sided colon cancer (RCC) is a demanding operation, especially when performed laparoscopically. The potential impact of CME in increasing postoperative complications is still unclear. The aim of our study was to evaluate the safety and feasibility of laparoscopic CME compared with laparoscopic non-complete mesocolic excision (NCME) during colectomy for RCC.

METHODS

Data from a prospectively collected database of patients who underwent laparoscopic right and extended right colectomy at our institution between January 2008 and February 2020 were retrieved and analyzed. Short-term outcomes of patients undergoing CME and NCME were compared. A 1:1 propensity score matching (PSM) was used to balance baseline characteristics between groups.

RESULTS

A total of 663 consecutive patients underwent resection of RCC in the study period. Among these, 500 met the inclusion criteria and after PSM a total of 372 patients were correctly matched, 186 in each group. A similar rate of overall postoperative complications was found between the CME and NCME groups (21.5% and 18.3%, p = 0.436). No difference was found in terms of conversion rate, severe complications, reoperations, readmissions, and mortality. The median number of harvested lymph nodes was higher in the CME group (22 versus 19, p = 0.003), with a lower rate of inadequate sampling (7.0% and 15.1%, p = 0.013).

CONCLUSION

Laparoscopic CME for RCC is technically feasible and safe. It does not seem to be associated with a higher rate of complications or mortality compared with the "traditional" approach, but it allows better nodal sampling.

Complete Mesocolic Excision and D3 Lymphadenectomy versus Conventional Colectomy for Colon Cancer: A Systematic Review and Meta-Analysis

BACKGROUNDS

Previous systematic reviews suggest that the implementation of 'complete mesocolon excision' (CME) for colon tumors entails better specimen quality but with limited long-term outcomes. We performed a meta-analysis to compare the pathological, perioperative, and oncological results of CME with conventional surgery (CS) in primary colon cancer.

METHODS

Embase, MEDLINE and CENTRAL databases were searched using Medical Subject Headings for CME and D3 lymphadenectomy. The systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines.

RESULTS

A total of 18,989 patients from 27 studies were included. Postoperative complications were higher in the CME group (relative risk [RR] 1.13, 95% confidence interval [CI] 1.04-1.22, I² = 0%), while no differences were observed in terms of anastomotic leak (I² = 0%) or perioperative mortality (I² = 49%). CME was associated with a higher number of lymph nodes harvested (I² = 95%), distance to high tie (I² = 65%), bowel length (I² = 0%), and mesentery area (I² = 95%). CME also had positive effects on 3- and 5-year overall survival (RR 1.09, 95% CI 1.04-1.15, I² = 88%; and RR 1.05, 95% CI 1.02-1.08, I² = 62%, respectively) and 3-year disease-free survival (RR 1.10, 95% CI 1.04-1.17, I² = 22%), as well as decreased local (RR 0.35, 95% CI 0.24-0.51, I² = 51%) and distant recurrences (RR 0.71, 95% CI 0.60-0.85, I² = 34%).

CONCLUSIONS

Limited evidence suggests that CME improves oncological outcomes with a higher postoperative adverse events rate but no increase in anastomotic leak rate or perioperative mortality, compared with CS.

[Metastasis of the right colon mucinous adenocarcinoma to aortocaval and retropancreatic space: case report and literature review]

Metastases of the right colon cancer to extra-regional lymph nodes are rarely observed. Available literature data cannot be a reliable guide to choose the optimal treatment strategy. Indeed, excision of extra-regional lymph nodes is a rare experience and its results are poorly represented. According to our clinical experience, surgical intervention following comprehensive examination may be radical in patients with right colon cancer if distant metastases are absent. Resection of extra-regional lymph nodes can be safely performed in these cases. We report a patient with the right colon cancer and lesion of extra-regional lymph nodes behind the pancreatic head, paracaval and paraaortic space, hepatoduodenal ligament. Standard laparoscopic right-sided hemicolectomy with D-3 lymph node dissection was accompanied by resection of a conglomerate of nodal metastases behind the pancreatic head and superficial resection of the pancreas. Extra-regional lymph node excision is a reasonable option for colon mucinous adenocarcinoma stage I-III. However, comprehensive preoperative examination is required. Technical difficulty of extra-regional lymph node excision it is not the reason for limitation of surgical intervention. However, safe and total resection requires an adequate surgical approach.

Comparison of Short-term Results after Laparoscopic Complete Mesocolic Excision and Standard Colectomy for Right-Sided Colon Cancer: Analysis of a Western Center Cohort

Purpose

Laparoscopic complete mesocolic excision (CME) right colectomy is a technically demanding procedure infrequently employed in Western centers. This retrospective cohort study aims to analyze the safety of laparoscopic CME colectomy compared to standard colectomy for right-sided colon cancer in a Western series.

Methods

Prospectively collected data from 60 patients who underwent laparoscopic CME right colectomy were compared to the ones of 55 patients who underwent laparoscopic standard right colectomy.

Results

No differences in clinical characteristics were observed between the CME and standard right colectomy groups. No differences were demonstrated in terms of blood loss (P = 0.060), intraoperative complications (P = 1), conversion rate (P = 0.102), and operative time (P = 0.473). No deaths were observed in either group, while complication rate was 40.0% in the CME and 49.1% in the standard group (P = 0.353). Severe complications occurred in 10.0% vs. 9.1% (P = 0.842), redo surgery in 5.0% vs. 7.3% (P = 0.708), and unplanned readmission in 5.0% vs. 5.5% (P = 1) after CME and standard colectomy, respectively. A significant difference in favor of CME was observed in the total length of specimen (P < 0.001), proximal (P = 0.018), and distal margins (P = 0.037). The number of lymph nodes harvested was significantly higher in the CME group (27 vs. 22, P = 0.037).

Conclusion

In Western series, where patients have less favorable clinical characteristics, laparoscopic CME allows to obtain better quality surgical specimens and comparable short-term outcomes compared to standard right colectomy.

Impact of D3 lymph node dissection on upstaging and short-term survival in clinical stage I right-sided colon cancer

BACKGROUND

D3 lymph node dissection is becoming the standard procedure for the treatment of advanced right colon cancer and has shown increasing evidence of its oncologic benefit. However, a clear indication for its application is lacking and data on this topic is unsatisfactory. Thus, the necessity for D3 lymph node dissection in clinical stage I right colon cancer remains controversial.

METHODS

We retrospectively analyzed data from clinical stage I right colon cancer patients who underwent radical surgery at three hospitals of Korea university medical center between January 2015 and June 2018. We compared surgical complications and short-term oncologic outcomes between D2 and D3 lymph node dissections in these patients.

RESULTS

Among 512 patients, 122 (23.8%) were clinical stage I. Of these, 88 and 34 patients received D2 and D3 lymph node dissection, respectively. There were no statistically significant differences in clinicopathologic variables and surgical outcomes between the two groups. Upstaging occurred in 16 patients (47.1%) in the D3 group and 23 patients (26.1%) in the D2 group. There were four recurrences in the D2 group but no recurrence in the D3 group. Log-rank tests showed no statistically significant difference in disease-free survival rates between the two groups (p = 0.210).

CONCLUSION

There was no significant difference in disease-free survival rates between D2 and D3 lymph node dissection in clinical stage I right colon cancer patients. However, recurrence occurred in the D2 group. Efforts to improve the accuracy of clinical staging are required and more studies with better quality are needed.

Laparoscopic Versus Open Right Colectomy for Cancer in the Era of Complete Mesocolic Excision with Central Vascular Ligation: Pathology and Short-Term Outcomes

Background: Colectomies performed according to complete mesocolic excision with central vascular ligation (CME-CVL) principles have been associated with enhanced oncologic outcomes. Nonetheless, laparoscopic CME-CVL right hemicolectomy has not been widely adopted. We aimed to compare the perioperative and pathology outcomes of laparoscopic and open CME-CVL right hemicolectomy. Materials and Methods: We compared data from a prospectively collected database regarding patients who underwent either laparoscopic or open CME-CVL right hemicolectomy for nonmetastatic right colon cancer in a University Hospital, between January 2012 and December 2018. Results: A total of 130 consecutive patients were included in the study. Of them, 73 patients underwent laparoscopic and 57 patients open right colectomy, following the CME-CVL principles. The laparoscopic approach was associated with less hospital stay (6.6 versus 9.1 days; P < .001) and septic complications (P = .046), at a cost of an increased operative time (180 versus 125.1 minutes; P < .001). Patients treated with either open or laparoscopic approach presented similar outcomes regarding pathology endpoints. In fact, both groups demonstrated similar R0 resection rate (P = .202), number of harvested and positive lymph nodes (P = .751 and P = .734, respectively), number of harvested lymph nodes at the level of D1 and D2 lymph node dissection (P > .05), rate of vascular (P = .501), and perineural infiltration (P = .956). Furthermore, no difference was found regarding the rate of intact mesocolic plane (P = .799), along with the tumor diameter (P = .154) and the length of specimen (P = .163). Conclusion: Laparoscopic CME-CVL right hemicolectomy appears to offer certain advantages in short-term outcomes compared to open procedure. Pathology outcomes did not differ between the two approaches. Future studies should further evaluate their long-term outcomes.

Short-term outcomes of complete mesocolic excision versus D2 dissection in patients undergoing laparoscopic colectomy for right colon cancer (RELARC): a randomised, controlled, phase 3, superiority trial

BACKGROUND

Whether extended lymphadenectomy for right colon cancer leads to increased perioperative complications or improves survival is still controversial. This trial aimed to compare the efficacy and safety of complete mesocolic excision (CME) versus D2 dissection in laparoscopic right hemicolectomy for patients with right colon cancer. This article reports the early safety results from the trial.

METHODS

This randomised, controlled, phase 3, superiority, trial was done at 17 hospitals in nine provinces of China. Eligible patients were aged 18-75 years with histologically confirmed primary adenocarcinoma located between the caecum and the right third of the transverse colon, without evidence of distant metastases. Central randomisation was done by means of the Clinical Information Management-Central Randomisation System via block randomisation (block size of four). Patients were randomly assigned (1:1) to CME or D2 dissection during laparoscopic right colectomy. Central lymph nodes were dissected in the CME but not in the D2 procedure. Neither investigators nor patients were masked to their group assignment but the quality control committee were masked to group assignment. The primary endpoint was 3-year disease-free survival, but the data for this endpoint are not yet mature; thus, only the secondary outcomes-intraoperative surgical complications and postoperative complications within 30 days of surgery, graded according to the Clavien-Dindo classification, mortality (death from any cause within 30 days of surgery), and central lymph node metastasis rate in the CME group only-are reported in this Article. This early analysis of safety was preplanned. The outcomes were analysed according to a modified intention-to-treat principle (excluding patients who no longer met inclusion criteria after surgery or who did not have surgery). This study is registered with ClinicalTrials.gov, NCT02619942. Study recruitment is complete, and follow-up is ongoing.

FINDINGS

Between Jan 11, 2016, and Dec 26, 2019, 1072 patients were enrolled and randomly assigned. After exclusion of 77 patients, 995 patients were included in the modified intention-to-treat population (495 in the CME group and 500 in the D2 dissection group). The postoperative surgical complication rate was 20% (97 of 495 patients) in the CME group versus 22% (109 of 500 patients) in the D2 group (difference, -2·2% [95% CI -7·2 to 2·8]; p=0·39); the frequency of Clavien-Dindo grade I-II complications were similar between groups (91 [18%] vs 92 [18%], difference, -0·0% [95% CI -4·8 to 4·8]; p=1·0) but Clavien-Dindo grade III-IV complications were significantly less frequent in the CME group than in the D2 group (six [1%] vs 17 [3%], -2·2% [-4·1 to -0·3]; p=0·022); no deaths occurred in either group. Of the intraoperative complications, vascular injury was significantly more common in the CME group than in the D2 group (15 [3%] vs six [1%], difference, 1·8 [95% CI 0·04 to 3·6]; p=0·045). Metastases in the central lymph nodes were detected in 13 (3%) of 394 patients who underwent central lymph node biopsy in the CME group; no patient had isolated metastases to central lymph nodes.

INTERPRETATION

Although the CME procedure might increase the risk of intraoperative vascular injury, it generally seems to be safe and feasible for experienced surgeons.

FUNDING

The Capital Characteristic Clinical Project of Beijing and the Chinese Academy of Medical Sciences.

Laparoscopic versus Open Complete Mesocolic Excision for Right Colon Cancer

Results

The mean operative time was significantly longer in the LCME group than that in the OCME group with less mean intraoperative blood loss. Conversion was required in 4 patients (8.3%) in the LCME group. The use of laparoscopy increased the number of harvested lymph nodes compared to the open approach (39.81 ± 16.74 vs. 32.65 ± 12.28, respectively, P=0.010). The laparoscopic approach was associated with a shorter time interval to first flatus as well as shorter time interval to liquid and normal diet after surgery. The postoperative hospital stay was significantly shorter in the LCME group. The complication rate was slightly lower in the LCME (14.7%) than in the OCME group (27.2%) (P=0.252). The 3-year OS in the LCME group was similar to that in OCME (78.2% vs. 63.2%, respectively, P value = 0.423). The three-year DFS in the laparoscopic group was higher (74.5%) than the open group (60.0%), but did not reach statistical significance (P value = 0.266).

Conclusions

In conclusion, laparoscopic CME right hemicolectomy is a technically feasible and safe procedure if surgeon expertise is present. LCME has long-term oncologic outcomes (recurrence and survival) comparable to open surgery for management of patients with stage II or III colon cancer.

Robotic Complete Mesocolic Excision (CME) is a safe and feasible option for right colonic cancers: short and midterm results from a single-centre experience

BACKGROUND

Complete mesocolic excision (CME) for right colon cancers has traditionally been an open procedure. Surgical adoption of minimal access CME remains limited due to the technical challenges, training gaps and lack of level-1 data for proven benefits. Currently there is limited published data regarding the clinical results with the use of robotic CME surgery. Aim To report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.

AIM

To report our experience, results and techniques, highlighting a clinical and oncological results and midterm oncological outcomes for robotic CME.

METHODS

All patients undergoing standardised robotic CME technique with SMV first approach between January 2015 and September 2019 were included in this retrospective review of a prospectively collected database. Patient demographics, operative data and clinical and oncological outcomes were recorded.

RESULTS

Seventy-seven robotic CME resections for right colonic cancers were performed over a 4-year period. Median operative time was 180 (128-454) min and perioperative blood loss was 10 (10-50) ml. There were 25 patients who had previous abdominal surgery. Median postoperative hospital stay was 5 (3-18) days. There was no conversion to open surgery in this series. Median lymph node count was 30 (10-60). Three (4%) patients had R1 resection. There was one (1%) local recurrence in stage III disease and 4(5%) distal recurrence in stage II and stage III. There was no 30- or 90-day mortality. Three-year disease-free survival was 100%, 91.7% and 92% for stages I, II and III, respectively. Overall survival was 94%.

CONCLUSIONS

Robotic CME is feasible, effective and safe. Good oncological results and improved survival are seen in this cohort of patients with a standardised approach to robotic CME.

Oncological reasons for performing a complete mesocolic excision: a systematic review and meta-analysis

BACKGROUND

While complete mesocolic excision (CME) has been shown to have an oncological benefit as compared to conventional colonic surgery for colon surgery, this benefit must be weighed up against the risk of major intra-abdominal complications. This paper aimed to assess the comparative oncological benefits of CME.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines, a systematic review of the literature until May 2020 was performed. Comparative studies assessing CME versus conventional colonic surgery for colon cancer were compared, and outcomes were pooled.

RESULTS

A total of 700 publications were identified, of which 19 were found to meet the inclusion criteria. A total of 25 886 patients were compared, with 14 431 patients in the CME arm. CME was associated with a significantly higher rate of vascular injury (odds ratio 3, P < 0.001). Rates of local and distant recurrence were lower in the CME group (odds ratio 0.66 and 0.73, respectively, both P < 0.001). CME patients had a significantly higher lymph node yield (P < 0.001). While no significant differences were noted between the two groups in terms of pooled 3- or 5-year disease-free survival, pooled 5-year overall survival was significantly higher in the CME group (relative risk 0.82, P < 0.001).

CONCLUSION

Based on the available evidence, CME is associated with improved oncologic outcomes at the expense of higher complication rates, including vascular injury. The oncological benefits need to weighed up against a multitude of factors including the level of hospital support, surgeon experience, patient age, and associated comorbidities.

Complete mesocolic excision in minimally invasive surgery of colonic cancer: do we need the robot?

Background

Robotic surgery offers favorable prerequisites for complex minimally invasive surgeries which are delivered by higher degrees of freedom, improved instrument stability, and a perfect visualization in 3D which is fully surgeon controlled. In this article we aim to assess its impact on complete mesocolic excision (CME) in colon cancer and to answer the question of whether the current evidence expresses a need for robotic surgery for this indication.

Methods

Retrospective analysis and review of the current literature on complete mesocolic excision for colon cancer comparing the outcome after open, laparoscopic, and robotic approaches.

Results

Complete mesocolic excision results in improved disease-free survival and reduced local recurrence, but turns out to be complex and prone to complications. Introduced in open surgery, the transfer to minimally invasive surgery resulted in comparable results, however, with high conversion rates. In comparison, robotic surgery shows a reduced conversion rate and a tendency toward higher lymph node yield. Data, however, are insufficient and no high-quality studies have been published to date. Almost no oncologic follow-up data are available in the literature.

Conclusion

The current data do not allow for a reliable conclusion on the need of robotic surgery for CME, but show results which hypothesize an equivalence if not superiority to laparoscopy. Due to recently published technical improvements for robotic CME and supplementary features of this method, we suppose that this approach will gain in importance in the future.

Prospective analysis of tumor spread to the small bowel mesentery in cases of right-sided colon cancer

PURPOSE

Guidelines advocate minimal ileal resection when right hemicolectomy is performed for right-sided colon cancer. The practice, thought to prevent malabsorption syndrome, does not appear to foster local recurrence. Little evidence based on rigorous study exists, however. To understand the pattern of lymphatic spread of right-sided colon cancer toward the small bowel and thus determine the appropriate margin size, we prospectively investigated anatomical distribution of lymph nodes (LNs) in the small bowel mesentery and of metastasis to these nodes in patients with right-sided colon cancer treated by such surgery.

METHODS

In each case, the mesenteric specimen, which had been dissected along the ileocolic vessels and included intermediate LNs, was divided into 2 areas: that 0-3 cm from the vessel pedicle (area 1) and that 3-5 cm from the pedicle (area 2). The peri-intestinal mesentery was cut into 9 segments.

RESULTS

Ninety-one patients were included in the study. Overall, 3366 LNs were dissected. Four hundred fifty-three of these LNs were located in area 1 (90 cases), and 15 (3.3%) were metastatic. Only 63 LNs were located in area 2 (34 cases; average of 0.69 per patient); none was metastatic. Overall, 269 LNs were found in the small bowel mesentery (in 56 of the 91 patients). Only 4 were positive (3 cases), and all were within 5 cm of the ileocecal valve.

CONCLUSION

Our data indicate that a surgical margin 3 cm from the ileocecal pedicle and a short (5 cm) ileal margin are oncologically reasonable for effective right hemicolectomy.

Comparing complete mesocolic excision versus conventional colectomy for colon cancer: A systematic review and meta-analysis

Conventional colectomy, and the Japanese Society for Cancer of the Colon and Rectum (JSCCR) D2 Lymphadenectomy (LND2), are currently considered standard of care for surgical management of colon cancer. Colectomy with complete mesocolic excision (CME) and JSCCR D3 Lymphadenectomy (LND3) are more radical alternative approaches and provide a greater degree of lymph nodal clearance. However, controversy exists over the long-term benefits of CME/LND3 over non-CME colectomies (NCME)/LND2. In this study, we performed a systematic review and meta-analysis to compare the surgical, pathological, and oncological outcomes of CME/LND3 with NCME/LND2. Embase, Medline and CENTRAL databases were searched from inception until May 15, 2020, in accordance with PRISMA guidelines. Studies were included if they compared curative intent CME/LND3 with NCME/LND2. Weighted mean differences (WMD) and odds ratios (OR) were estimated for continuous and dichotomous outcomes respectively. Out of 1310 unique citations, 106 underwent full-text review, and 30 were included for analysis. In total, 21,695 patients underwent resection for colon cancer. 11,625 received CME/LND3, and 10,070 underwent NCME/LND2. No significant differences were found in post-operative morbidity and mortality. Both overall and disease-free survival favored CME/LND3 (5-year OS: OR = 1.29; 95% CI 1.02 to 1.64, p = 0.03; 5-year DFS: OR = 1.61; 95% CI 1.14 to 2.28; p = 0.007). This is the first systematic review and meta-analysis to demonstrate that CME/LND3 has superior long-term survival outcomes compared to NCME/LND2.

Laparoscopic complete mesocolic excision with D3 lymph node dissection for right colon cancer in elderly patients

Complete mesocolic excision (CME) with D3 lymph node dissection is considered an oncological surgery for right colon cancer. However, there is still controversy for extensive oncological surgery in elderly patients. The aim of this study is to evaluate the safety and oncological outcomes of laparoscopic CME with D3 lymph node dissection for right colon cancer in elderly patients. Patients who underwent laparoscopic right colectomy, from 2004 to 2014, were divided into Groups A (age ≥ 70 years, n = 80) or B (age < 70 years, n = 127). Short and long-term outcomes were analysed. Basic demographics and short-term surgical outcomes were similar between groups. Among pathological outcomes, the mean number of harvested lymph nodes was significantly less in Group A. Adjuvant chemotherapy refusal rate was significantly higher in Group A. Overall and recurrence-free survival were similar between groups. We found laparoscopic CME with D3 lymph node dissection is a safe and feasible surgical option for right colon cancer in elderly patients.

Optimal extent of central lymphadenectomy for right-sided colon cancers: is lymphadenectomy beyond the superior mesenteric vein meaningful?

PURPOSE

The objective of the current study was to assess the therapeutic benefit of lymphadenectomy according to the extent of lymphadenectomy.

METHODS

Patients undergoing colectomy for right-sided colon cancer were identified. Distribution of lymph node metastases (DLNM) of 1, 2 and 3 were defined as lymph node metastasis (LNM) in the pericolic nodes, the intermediate nodes and the front of the SMV near the origin of the major artery, respectively. The therapeutic index (TI) was calculated based on the frequency of LNM and the 5 year overall survival (OS) rate of patients with LNM.

RESULTS

Among 344 patients who met the inclusion criteria, roughly half had LNM (n = 150, 43.7%). While 107 (31.1%) and 30 (8.7%) patients had DLNM1 and DLNM2, respectively, only 13 patients (3.8%) were defined as DLNM3. However, there was no significant difference in 5 year OS by DLNM (DLNM1 71.1%, DLNM2 78.7%, DLNM3 50.4%, p = 0.61). Overall, the TI of lymphadenectomy for D3 area was approximately 1/10 of the TI for D1 (1.9 vs.22.1), given the low frequency of LNM (3.8%) and poor 5 year OS of patients with LNM (50.4%). This trend was consistent irrespective of primary tumor locations.

CONCLUSION

The survival benefit from central lymphadenectomy namely D3 was low among patients with right-sided colon cancers.

Challenges of improving treatment outcomes for colorectal and anal cancers in Japan: the Colorectal Cancer Study Group (CCSG) of the Japan Clinical Oncology Group (JCOG)

Colorectal cancer is a major public health concern in Japan. While early-stage colorectal adenocarcinoma treatment entails radical resection of the primary tumor, the importance of perioperative treatment is growing as physicians seek to further improve treatment outcomes. For anal squamous cell carcinoma, definitive chemoradiotherapy is superior to radical surgery in terms of improved patient quality of life. The Colorectal Cancer Study Group of the Japanese Clinical Oncology Group was established in 2001 and has worked to provide answers to common clinical questions and improve treatment outcomes for colorectal and anal cancers through 15 large-scale prospective clinical trials. Here, we discuss the current state of perioperative treatment for early-stage colon, rectal and anal cancers in Japan and approaches taken by the Colorectal Cancer Study Group/the Japanese Clinical Oncology Group to improve treatment outcomes for these cancers.