Pathologic factors are more important than tumor location in long-term survival in colon cancer

Oncologic outcomes after laparoscopic versus open multivisceral resection for local advanced colorectal cancer: A meta-analysis

Laparoscopic (lap) colectomies for advanced colorectal cancer (CRC) often require resection of other organs. We systematically reviewed currently available literature on lap multi-visceral resection for CRC, with regard to short- and long-term oncological outcomes, and compared them with open procedures. We performed a systematic literature search in MEDLINE, EMBASE, Google Scholar and PubMed from inception to November 30, 2020. The aim of this study was to synthesize short-term and oncological outcomes associated with laparoscopic versus open surgery. Pooled proportions and risk ratios (RRs) were calculated using an inverse variance method. We included six observational cohort studies published between 2012 and 2020 (lap procedures: n = 262; open procedures: n = 273). Collectively, they indicated that postoperative complications were significantly more common after open surgeries than lap surgeries (RR: 0.53; 95% confidence interval [CI]: 0.39-0.72; P < 0.00001), but the two approaches did not significantly differ in positive resection margins (RR: 0.75; 95% CI: 0.38-1.50; P = 0.42), local recurrence (RR: 0.66; 95% CI: 0.28-1.62; P = 0.37), or (based on two evaluable studies) 5-year OS (RR: 0.70; 95% CI: 0.46-1.04; P = 0.08) or 5-year DFS (RR: 0.86; 95% CI: 0.67-1.11) for T4b disease. In conclusion, laparoscopic and open multi-visceral resections for advanced CRC have comparable oncologic outcomes. Although a randomized study would be ideal for further research, no such studies are currently available.

Minimally invasive vs. open segmental resection of the splenic flexure for cancer: a nationwide study of the Italian Society of Surgical Oncology-Colorectal Cancer Network (SICO-CNN)

BACKGROUND

Evidence on the efficacy of minimally invasive (MI) segmental resection of splenic flexure cancer (SFC) is not available, mostly due to the rarity of this tumor. This study aimed to determine the survival outcomes of MI and open treatment, and to investigate whether MI is noninferior to open procedure regarding short-term outcomes.

METHODS

This nationwide retrospective cohort study included all consecutive SFC segmental resections performed in 30 referral centers between 2006 and 2016. The primary endpoint assessing efficacy was the overall survival (OS). The secondary endpoints included cancer-specific mortality (CSM), recurrence rate (RR), short-term clinical outcomes (a composite of Clavien-Dindo > 2 complications and 30-day mortality), and pathological outcomes (a composite of lymph nodes removed ≧12, and proximal and distal free resection margins length ≧ 5 cm). For these composites, a 6% noninferiority margin was chosen based on clinical relevance estimate.

RESULTS

A total of 606 patients underwent either an open (208, 34.3%) or a MI (398, 65.7%) SFC segmental resection. At univariable analysis, OS and CSM were improved in the MI group (log-rank test p = 0.004 and Gray's tests p = 0.004, respectively), while recurrences were comparable (Gray's tests p = 0.434). Cox multivariable analysis did not support that OS and CSM were better in the MI group (p = 0.109 and p = 0.163, respectively). Successful pathological outcome, observed in 53.2% of open and 58.3% of MI resections, supported noninferiority (difference 5.1%; 1-sided 95%CI - 4.7% to ∞). Successful short-term clinical outcome was documented in 93.3% of Open and 93.0% of MI procedures, and supported noninferiority as well (difference - 0.3%; 1-sided 95%CI - 5.0% to ∞).

CONCLUSIONS

Among patients with SFC, the minimally invasive approach met the criterion for noninferiority for postoperative complications and pathological outcomes, and was found to provide results of OS, CSM, and RR comparable to those of open resection.

Mid-transverse Location in Primary Colon Tumor: A Poor Prognostic Factor?

BACKGROUND

The location of colonic tumors has been linked to different clinical and oncologic outcomes. Transverse colon cancers are generally included as right colon cancers. Furthermore, hepatic and splenic flexure tumors are usually included as components of the transverse colon.

OBJECTIVE

This study was aimed at comparing the clinicopathologic characteristics and long-term outcomes between mid-transverse and right and left colon cancers and determining the prognostic impact of the primary tumor location in the mid-transverse colon.

DESIGN

This was a retrospective study.

SETTINGS

Two specialized colorectal centers were included.

PATIENTS

Patients who underwent curative surgery for colon cancer were analyzed. Tumors located in the transverse colon, excluding the flexures, were defined as mid-transverse colon cancers.

MAIN OUTCOME MEASURES

Demographic characteristics, operative outcomes, pathologic results, and long-term outcomes were the primary outcome measures.

RESULTS

Of the 487 patients, 41 (8.4%) had mid-transverse, 191 (39.2%) had right, and 255 (52.4%) had left colon cancers. For mid-transverse colon cancers, the mean length of hospital stay, mean length of the resected specimen, and the mean number of harvested lymph nodes were significantly higher. For patients with stage I to III cancer, the 5-year overall and disease-free survival rates were significantly worse in the mid-transverse colon cancers than in the right and left colon cancers (overall survival: 55.5% vs 82.8% vs 85.9%, p = 0.004, and disease-free survival; 47.7% vs 72.4% vs 79.5%, p = 0.003). After adjustment for other clinicopathologic factors, mid-transverse colon cancers were significantly associated with a poor prognosis (HR = 2.19 [95% CI, 1.25-3.83]; p = 0.006).

LIMITATIONS

Molecular and genetic information were unavailable in this retrospective study.

CONCLUSIONS

In our case series, colon cancers located in the mid-transverse colon showed poorer prognosis than cancers in other locations. The impact of tumor location in the mid-transverse colon on prognosis, including molecular and genetic markers, should be investigated further in prospective studies. See Video Abstract at http://links.lww.com/DCR/B631.

LOCALIZACIN TRANSVERSA MEDIA EN EL TUMOR DE COLON PRIMARIO UN FACTOR DE MAL PRONSTICO

ANTECEDENTES:La ubicación de los tumores de colon se ha relacionado con diferentes resultados clínicos y oncológicos. Los cánceres de colon transverso se incluyen generalmente como cánceres de colon derecho. Además, los tumores del ángulo hepático y esplénico suelen incluirse como un componente del colon transverso.OBJETIVO:Este estudio tuvo como objetivo comparar las características clínico-patológicas y los resultados a largo plazo entre los cánceres de colon transverso medio y derecho e izquierdo y determinar el impacto pronóstico de la ubicación del tumor primario en el colon transverso medio.DISEÑO:Este fue un estudio retrospectivo.AJUSTE ENTORNO CLINICO:Se incluyeron dos centros colorrectales especializados.PACIENTES:Se analizaron los pacientes que fueron sometidos a cirugía curativa por cáncer de colon. Los tumores ubicados en el colon transverso, excluidos los ángulos, se definieron como "cánceres de colon transverso medio".PRINCIPALES MEDIDAS DE RESULTADO VOLARACION:Las características demográficas, los resultados quirúrgicos, los resultados patológicos y los resultados a largo plazo fueron las principales medidas de resultado valoracion.RESULTADOS:De los 487 pacientes, 41 (8,4%) tenían cáncer de colon transverso medio, 191 (39,2%) derecho y 255 (52,4%) cáncer de colon izquierdo. Para los cánceres de colon transverso medio, la duración media de la estancia hospitalaria, la duración de la muestra resecada y el número medio de ganglios linfáticos extraídos fueron significativamente mayores. Para los pacientes en estadio I-III, las tasas de supervivencia general y sin enfermedad a 5 años fueron significativamente peores en los cánceres de colon transverso medio que en los cánceres de colon derecho e izquierdo (supervivencia general: 55,5% frente versus a 82,8% frente versus a 85,9%, p = 0,004 y supervivencia libre de enfermedad; 47,7% frente a 72,4% frente a 79,5%, p = 0,003, respectivamente). Después del ajuste por otros factores clínico-patológicos, los cánceres de colon transverso medio se asociaron significativamente con un pronóstico desfavorable (Razón de riesgo: 2,19; intervalo de confianza del 95%: 1,25-3,83; p = 0,006).LIMITACIONES:La información molecular y genética no estuvo disponible en este estudio retrospectivo.CONCLUSIONES:En nuestra serie de casos, los cánceres de colon localizados en el colon transverso medio mostraron un peor pronóstico que los cánceres en otras localizaciones. El impacto de la ubicación del tumor en el colon transverso medio sobre el pronóstico, incluidos los marcadores moleculares y genéticos, debe investigarse más a fondo en estudios prospectivos. Consulte Video Resumen en http://links.lww.com/DCR/B631. (Traducción-Dr Adrián Ortega).

Prognostic analysis and beneficiary identification of adjuvant external beam radiotherapy for stage pT4b sigmoid colon cancer

The clinical efficacy of adjuvant radiotherapy in sigmoid colon cancer remains questioned. To evaluate the clinical efficacy of adjuvant external beam radiotherapy (EBRT) for patients with pathologic stage T4b sigmoid colon cancer. Patients with stage pT4b sigmoid colon cancer receiving adjuvant EBRT or not followed by surgery between 2004 and 2016 were extracted from the Surveillance, Epidemiology, and End Results database. Analysis of overall survival (OS) was performed using Kaplan-Meier curves and prognostic factors were identified using Cox proportional hazards regression models with 95% confidence intervals within the entire cohort. A risk-stratification system was then developed based on the β regression coefficient. Among 2073 patients, 284 (13.7%) underwent adjuvant EBRT. The median OS in the group receiving adjuvant EBRT was significantly longer than that in the non-radiotherapy group (p < 0.001). Age, serum carcinoembryonic antigen (CEA) level, perineural invasion, lymph node dissection (LND) number, and adjuvant EBRT were independent factors associated with OS. A risk-stratification system was generated, which showed that low-risk patients had a higher 5-year survival rate than high-risk patients (75.6% vs. 42.3%, p < 0.001). Adjuvant EBRT significantly prolonged the 5-year survival rate of high-risk patients (62.6% vs. 38.3%, p = 0.009) but showed no survival benefit among low-risk patients (87.7% vs. 73.2%, p = 0.100). Our risk-stratification model comprising age, serum CEA, perineural invasion, and LND number predicted the outcomes of patients with stage pT4b sigmoid colon cancer based on which subgroup of high-risk patients should receive adjuvant EBRT.

Are there sex differences among colorectal cancer patients in treatment and survival? A Swiss cohort study

BACKGROUND

Colorectal cancer (CRC) is among the three most common incident cancers and causes of cancer death in Switzerland for both men and women. To promote aspects of gender medicine, we examined differences in treatment decision and survival by sex in CRC patients diagnosed 2000 and 2001 in the canton of Zurich, Switzerland.

METHODS

Characteristics assessed of 1076 CRC patients were sex, tumor subsite, age at diagnosis, tumor stage, primary treatment option and comorbidity rated by the Charlson Comorbidity Index (CCI). Missing data for stage and comorbidities were completed using multivariate imputation by chained equations. We estimated the probability of receiving surgery versus another primary treatment using multivariable binomial logistic regression models. Univariable and multivariable Cox proportional hazards regression models were used for survival analysis.

RESULTS

Females were older at diagnosis and had less comorbidities than men. There was no difference with respect to treatment decisions between men and women. The probability of receiving a primary treatment other than surgery was nearly twice as high in patients with the highest comorbidity index, CCI 2+, compared with patients without comorbidities. This effect was significantly stronger in women than in men (p-interaction = 0.010). Survival decreased with higher CCI, tumor stage and age in all CRC patients. Sex had no impact on survival.

CONCLUSION

The probability of receiving any primary treatment and survival were independent of sex. However, female CRC patients with the highest CCI appeared more likely to receive other therapy than surgery compared to their male counterparts.

Effect of sidedness on survival among patients with early-stage colon cancer: a SEER-based propensity score matching analysis

BACKGROUND

Most previous studies compared survival between left-sided and right-sided colon cancer without adjustment for clinicopathological parameters. We investigated the effect of sidedness on survival among patients with early-stage colon cancer, using a propensity score matching method.

METHODS

The 18 registry custom data within the SEER database were used to identify patients who were diagnosed with colon cancer between 2010 and 2014. A propensity score matching analysis was performed using the nearest neighbor method. Survival was estimated using the Kaplan-Meier method. A Cox proportional hazards model was applied to determine the prognostic factors.

RESULTS

In the unmatched cohort, 25,094 (35.72%) patients were diagnosed with left-sided colon cancer and 45,156 (64.28%) with right-sided colon cancer. After propensity score matching, each cohort included 5118 patients, and the clinicopathological characteristics were well balanced. In the unmatched cohort, left-sided colon cancer had superior all-cause (χ²=315, P<0.01) and cancer-specific (χ²=43, P<0.01) survival than right-sided tumors. However, in the matched cohort, no difference was observed for all-cause (χ²=0.7, P=0.4) and cancer-specific (χ²=0, P=0.96) survival between left and right colon cancer. The Cox model did not indicate sidedness as a prognostic factor. In the subgroup analysis, stage II right-sided colon cancer had a better survival outcome, while stage III left-sided tumors had a better survival outcome.

CONCLUSIONS

After adjusting for clinicopathological characteristics in this study, sidedness showed no impact on survival in early-stage colon cancer. However, sidedness was associated with prognostic differences in stages II and III early-stage colon cancer.

Left colon as a novel high-risk factor for postoperative recurrence of stage II colon cancer

Background

It is not clear whether stage II colon and rectal cancer have the same risk factors for recurrence. Thus, the purpose of this study was to identify the risk factors for postoperative recurrence in stage II colorectal cancer.

Patients and methods

We retrospectively analyzed the data of 990 patients who had undergone radical surgery for stage II colorectal cancer. Patients’ pathological features and characteristics including age, sex, family history, body mass index, tumor diameter, gross type of tumor, infiltration degree (T3/T4), tumor grade, perineural invasion, vascular invasion, lymphatic invasion, pathologic examination of lymph node number, and preoperative carcinoembryonic assay (CEA) level was compared between patients with and without recurrence. Finally, the prediction of the left and right colons was analyzed.

Results

The mean ages of the colon cancer and rectal cancer patients were 69.5 years and 66.4 years, respectively. In total, 508 (82.1%) and 285 (76.8%) patients were treated laparoscopically for colon cancer and rectal cancer, respectively, with median follow-up periods of 42.2 months and 41.8 months, respectively. Forty-four recurrences occurred in both the colon cancer (7.1%) and rectal cancer (11.9%) groups. The preoperative serum CEA level and T4 infiltration were significantly higher in recurrent colorectal cancer patients. The postoperative recurrence rate of left colon cancer (descending colon, sigmoid colon) was higher than that of right colon cancer (cecum, ascending colon, transverse colon) (OR 2.191, 95% CI 1.091–4.400, P = 0.027). In COX survival factor analysis of colon cancer, the left colon is one of the independent risk factors (risk ratio 5.377, 95% CI 0.216–0.88, P = 0.02). In disease-free survival (DFS), the left colon has a relatively poor prognosis (P = 0.05). However, in the COX analysis and prognosis analysis of OS, no difference was found between the left colon and the right colon.

Conclusion

Preoperative CEA and depth of infiltration (T4) are high-risk factors associated with recurrence and are prognostic factors in stage II colorectal cancer. Left colon is also a risk factor for postoperative recurrence of stage II colon cancer.

Two sides to colon cancer: mice mimic human anatomical region disparity in colon cancer development and progression

Aim:

Strong evidence reveals important differences between cancers in the proximal vs. distal colon. Animal models of metastatic colon cancer are available but with varying degrees of reproducibility and several important limitations. We explored whether there were regional differences in the location of murine colon cancers and assessed the utility of murine models to explore the biological basis for such differences.

Methods:

We re-analyzed data from our previous studies to assess the regional distribution of murine colon cancer. In survival surgery experiments, we injected HT-29 human colon cancer cells into the wall of the cecum or distal colon of Nu(NCr)-Foxn1^nu or NOD.Cg-Prkdc^scidIl2rg^Tim1Wji/SzJ mice and compared the development of primary tumors and metastases.

Results:

Within 7–17 weeks after intramural cecal injection of HT-29 cells, eight mice failed to develop solid primary tumors or metastases. In contrast, within four weeks after cell injection into the distal colon, 13 mice developed metastases - 12 mice developed subcutaneous metastases; of these, four developed liver metastases and one developed both liver and lung metastases. One mouse developed liver metastases only. Histological examination confirmed these lesions were adenocarcinomas.

Conclusion:

Our findings reveal the preferential growth of murine colon neoplasia and invasive human orthotopic xenografts in the distal mouse colon. The new approach of injecting cells into the distal colon wall results in a pattern of colon cancer development that closely mimics the progression of metastatic colon cancer in humans. This novel model of colon neoplasia has great potential for exploring anatomical differences in colon cancer and testing novel therapeutics.

Oncological outcomes of laparoscopic versus open surgery in pT4 colon cancers: A systematic review and meta-analysis

BACKGROUND

Widespread adoption of minimally invasive surgery for colon cancer has achieved improved short-term benefits and better long-term oncological outcomes compared with open surgery. However, it is still controversial whether laparoscopic surgery is suitable for patients with stage T4 colon cancer. The aim of this meta-analysis was to compare short- and long-term oncological outcomes associated with laparoscopic and conventional open surgery for pT4 colon cancer.

METHODS

Published studies from 2003 to 2018 comparing oncological outcomes following laparoscopic and open surgery for pT4 colon cancer were systematically searched. Data on conversion rate, R0 resection rate, number of harvested lymph nodes, morbidity and mortality, and overall survival (OS) and disease-free survival (DFS) were subjected to meta-analysis using fixed-effect and random-effect models.

RESULTS

Twelve observational studies met the inclusion criteria with a total of 2396 cases (1250 laparoscopic and 1146 open). There was no significant difference in R0 resection rate [relative risk (RR) = 1.007; 95% confidence interval (CI) = 0.935-1.085; P = 0.850], number of harvested lymph nodes (MD = 0.004; 95% CI = -0.139 to 0.148; P = 0.951), mortality (RR = 0.509; 95% CI = 0.176-1.470; P = 0.212), and 3-year OS (RR = 1.056; 95% CI = 0.939-1.188; P = 0.360), 5-year OS (RR = 1.003; 95% CI = 0.883-1.139; P = 0.966), 3-year DFS (RR = 1.032; 95% CI = 0.903-1.179; P = 0.642), and 5-year DFS (RR = 0.995; 95% CI = 0.868-1.140; P = 0.973) between the groups. The rate of conversion from laparoscopic to open procedures was 10.7% (95% CI = 0.090-0.124). There was a significant difference in incidence of complications within 30 postoperative days between laparoscopic and open surgery (RR = 0.703; 95% CI = 0.564-0.876; P = 0.002).

CONCLUSION

Laparoscopic surgery is safe and feasible in pT4 colon cancer, oncological outcomes are similar, and more importantly, there are fewer postoperative complications compared with open surgery.