Adenocarcinoma of the Rectum-A Composite of Three Different Subtypes With Varying Outcomes?

What are the preoperative predictors of a futile pelvic exenteration in rectal cancers?

INTRODUCTION

Early recurrences and deaths after a morbid procedure like pelvic exenteration are devastating events. The present study aimed at determining the incidence and predictors of futile pelvic exenterations.

METHODS

Consecutive pelvic exenterations for advanced and recurrent rectal adenocarcinomas operated between January 2013 and January 2021 were included with a minimum of six months follow-up. Futility of exenteration was defined as recurrence or death within six months of operation. Multivariate logistic regression was used to define predictors of futility.

RESULTS

Two-hundred eighty-five patients were included and 61 patients (21.4%) had a futile resection. Poorly differentiated (or signet) histology, presence of lateral pelvic nodes, M1 disease, and the need for pelvic bone resections predicted a futile resection. The probability of futility was 10%, 20%, 35-40%, 55-60%, and >75% when none, one, two, three, and all four of the predictors were present. The model was able to correctly predict futility in 70% of the cases suggesting moderate discrimination, and showed good calibration.

CONCLUSIONS

Futile pelvic exenterations were observed in one-fifth of patients. Four strong predictors of futility were identified. The risk of early failures was additive when combination of these adverse features was present, and can be used for patient selection and prognostication.

Construction of Novel Prognostic Nomogram for Mucinous and Signet Ring Cell Colorectal Cancer Patients with a Survival Longer Than 5 Years

Purpose

Patients and Methods

Results

Conclusion

Minimally invasive versus open pelvic exenterations for rectal cancer: a comparative analysis of perioperative and 3-year oncological outcomes

BACKGROUND

This study compared the surgical and oncological outcomes of open and minimally invasive pelvic exenteration.

METHODS

Patients who underwent pelvic exenterations for primary locally advanced rectal cancers with invasion of the urogenital organs (central and anterior disease) between August 2013 and September 2020 were reviewed retrospectively. Patients were categorized as undergoing open or minimally invasive surgery (MIS) and these groups were compared for perioperative outcomes and 3-year survival (overall, recurrence-free and local relapse-free survival). Multivariable Cox regression analysis was performed to assess the independent influence of approach of surgery and cancer features on recurrence-free survival (RFS).

RESULTS

Of the 158 patients who underwent pelvic exenteration, 97 (61.4 per cent) had open exenterations and 61 (38.6 per cent) patients had an MIS resection (44 patients (72 per cent) using laparoscopy and 17 (28 per cent) using robotic surgery). There were 96 (60.8 per cent) total pelvic exenterations and 62 (39.2 per cent) posterior pelvic exenterations. MIS exenterations had significantly longer operative times (MIS versus open: 640 mins versus 450 mins; P < 0.001) but reduced blood loss (MIS versus open: 900 ml versus 1600 ml; P < 0.001) and abdominal wound infections (MIS versus open: 8.2 versus 17.5 per cent; P = 0.020) without a difference in hospital stay (MIS versus open: 11 versus 12 days; P = 0.620). R0 resection rates and involvement of circumferential resection margins were similar (MIS versus open: 88.5 versus 91.8 per cent, P = 0.490 and 13.1 versus 8.2 per cent, P = 0.342 respectively). At a median follow-up of 29 months, there were no differences in 3-year overall survival (MIS versus open: 79.4 versus 60.2 per cent; P = 0.251), RFS (MIS versus open: 51.9 versus 47.8 per cent; P = 0.922) or local relapse-free survival (MIS versus open: 89.7 versus 75.2 per cent; P = 0.491. On multivariable analysis, approach to surgery had no bearing on RFS, and only known distant metastasis, aggressive histology and inadequate response to neoadjuvant radiation (pathological tumour regression grade greater than 3) predicted worse RFS.

CONCLUSION

MIS exenterations documented longer procedures but resulted in less blood loss and fewer wound infections compared with open surgeries. In the setting of an experienced centre, the hospital stay, R0 resection rates and oncological outcomes at 3 years were similar to those of open exenterations.

Local recurrence with intersphincteric resection in adverse histology rectal cancers. A retrospective study with competing risk analysis

BACKGROUND

The safety of inter-sphincteric resection (ISR) for low rectal cancer with adverse histologic subtypes has been incompletely studied. The present study aims at determining the risk of local recurrence with this procedure in poorly differentiated and signet ring cell (PDSR) adenocarcinoma.

METHODS

Retrospective analysis from a single tertiary cancer centre of non-metastatic primary rectal cancer <6 cm from the anal verge that underwent ISR. Competing risk analysis and sub-distribution hazard ratios for local recurrence free survivals were calculated to determine factors that influenced local recurrence with the competing risk of death from any cause to overcome the exceeding risk of distant metastasis associated with adverse histologic types.

RESULTS

One hundred forty-two patients underwent ISR and 22.6% has PDSR histology. At a median follow up of 61 months, 15.6% of the PDSR cohort developed local recurrence (five patients) compared to 11.7% in the non-PDSR group. PDSR histology influenced overall and disease free survival but not local recurrence on cox regression. On competing risk analysis, only ypT stage ≥3 predicted worse local recurrence free survival and not histology.

CONCLUSIONS

The presence of PDSR histology did not increase the risk of local recurrence after ISR in this retrospective competing risk analysis.

Optimal neoadjuvant strategy for signet ring cell carcinoma of the rectum-Is TNT the solution?

INTRODUCTION

The results of total neoadjuvant therapy (TNT) for locally advanced rectal cancers (LARC) cannot be extrapolated to signet-ring cell cancers (SRCC) that have an extremely aggressive biology.

METHODS

A retrospective study comparing long course chemoradiation (CTRT) against short course radiation (SCRT) and 12 weeks of chemotherapy for high-risk LARC. Primary endpoints were treatment failure and disease-free survival (DFS) RESULTS: CTRT was given to 74 (59.7%) and SCRT/Chemotherapy to 50 patients (40.3%). Additional chemotherapy was required in 54.1% and 28%, respectively. Except for nodal staging, no other MRI parameter down-staged. Treatment failures were seen in 33.9% and 25.8% had progression. The peritoneum was the commonest site of progression (59.4%). Of the patients that were surgically explored, 63.7% had R0 resections and pathological complete response was seen in 9.7%. At a median follow-up of 35 months, 56.5% had DFS events with a 3-year DFS of 39.5%. Recurrences were noted in 45.1% after curative resections and the 3-year OS/DFS of these patients were 67.2%/56.4%. On multivariate regression, the type of preoperative therapy did not influence treatment failures or DFS.

CONCLUSIONS

SRCC is a very aggressive disease and none of the treatment strategies could show superiority over the other with very high peritoneal progression rates and relapses.

Clinicopathological Features and Survival of Signet-Ring Cell Carcinoma and Mucinous Adenocarcinoma of Right Colon, Left Colon, and Rectum

Histological subtype plays an important role in the different clinical characteristics and survival outcomes of patients with colorectal carcinoma (CRC). However, in previous studies, the influences of tumor locations and tumor stages have not been strictly controlled. This study focused on the assessment of the prognostic value of each histological subtype in different tumor locations and tumor stages of CRC. We used the Surveillance, Epidemiology, and End Results (SEER) database (1973-2011) to analyze 818,229 CRC patients with different clinical and pathological features, and analyzed the prognostic value of each histological subtype. Under the condition of stratification by tumor stage, signet-ring cell carcinoma (SRCC) presented the worst survival in each stage of right colon cancer (stage I, log-rank, p = 0.002, stages II, III, and IV, log-rank, p < 0.001), rectal cancer (RC) (log-rank, p < 0.001), and in stages II, III, and IV of left colon cancer (log-rank, p < 0.001). Multivariate survival analysis suggested SRCC subtype, male gender, age ≥ 70 years, tumor size ≥ 5 cm, stage progression, and poor differentiation were all significant factors worsening survival in CRC (p < 0.001, respectively). Mucinous adenocarcinoma (MC) histological subtype proved to be an independent protective factor for the prognosis of right colon cancer (p = 0.003). Overall, in our study, the results suggested SRCC had the worst survival among the three histological subtypes of CRC. MC was associated with favorable prognosis in right colon cancer but not with other tumor locations.

Prognostic value of metabolic parameters on 18F-fluorodeoxyglucose positron tomography/computed tomography in classical rectal adenocarcinoma

We aimed to investigate the prognostic value of the metabolic parameters of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) in classical rectal adenocarcinoma (CRAC). We retrospectively reviewed 149 patients with CRAC who underwent preoperative ¹⁸F-FDG PET/CT at initial diagnosis followed by curative surgical resection. ¹⁸F-FDG PET/CT metabolic parameters including maximum standardized uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) for disease-free survival (DFS) and overall survival (OS) were evaluated for prognostic significance by univariate and multivariate analyses, along with conventional risk factors including pathologic T (pT) stage, lymph node (LN) metastasis, lymphovascular invasion (LVI), perineural invasion (PNI), and preoperative carcinoembryonic antigen (CEA) level. On univariate analysis, high pT stage, positive LN metastasis, LVI, PNI, MTV, and TLG were significant prognostic factors affecting DFS (all P < 0.05), while CEA level, high pT stage, positive LN metastasis, LVI, PNI, MTV, and TLG affected OS (all P < 0.05). On multivariate analysis, positive LN metastasis, LVI, MTV, and TLG were independent prognostic factors affecting DFS (all P < 0.05), while CEA level, positive LN metastasis, and MTV affected OS (all P < 0.05). Thus, the volume-based metabolic parameters from preoperative ¹⁸F-FDG PET/CT scans are independent prognostic factors in patients with CRAC.

Long-term oncological outcomes of the sphincter preserving total mesorectal excision with varying distal resection margins

INTRODUCTION

A subcentimeter distal resection margin (DRM) appears to be acceptable for most patients, however, long-term follow up and specific subsets where DRM would influence recurrences have not been adequately investigated.

METHODS

A retrospective analysis of all sphincter-preserving resections for mid and low rectal cancers between July 2011 and May 2015 was performed. Extended total mesorectal excisions (TME) and patients with positive pathologic circumferential margins (CRM) were excluded.

RESULTS

Two hundred and thirty-six patients fit the inclusion criteria. DRM > 20 mm was obtained in 117 patients (49.6%), between 10 and 20 mm in 78 (33%) and <10 mm in 41 (17.4%) patients. Pathological DRM was positive in 4 patients (1.7%). Sixty-five recurrences occurred at a median follow up of 78.5 months. DRM did not influence any of the oncological outcomes. In a subset analysis of patients with poor pathological response to neoadjuvant radiation, that is, tumor regression grade > 3, DRM influenced disease-free survival (DFS) but not overall survival with a hazard ratio of 4.4 (p = 0.02). This was confirmed on multivariate regression analysis in this subgroup as well where pathological nodal status and DRM < 10 mm were independent predictors of DFS.

CONCLUSIONS

A subcentimeter DRM may be acceptable in most patients except those who have an inadequate response to neoadjuvant radiation.

Clinical impact of non-predominant histopathological subtypes on the long-term prognosis of colorectal cancer patients in Japan

PURPOSE

We performed a retrospective study to clarify the long-term prognosis of patients with histopathological high-grade colorectal cancer (CRC).

METHODS

We reviewed data from 24 institutions for 18,360 patients with pStage I to III CRC who had undergone curative surgery between 2004 and 2012. The patients were classified into seven groups according to the proportion of the histopathological component: classical adenocarcinoma (CAC) group, M-l and M-h groups (< 50% and ≥ 50% mucinous adenocarcinoma, respectively), P-l and P-h groups (< 50% and ≥ 50% poorly differentiated adenocarcinoma, respectively), and S-l and S-h groups (< 50% and ≥ 50% signet-ring cell carcinoma (SRCC), respectively).

RESULTS

The 5-year recurrence-free survival (RFS) rates of the M-l, P-l, and S-l groups were 75.5%, 68.4%, and 52.4%, respectively, and were significantly lower than those of the CAC group (83.5%, hazard ratio [HR] 1.22, 95% confidence interval [CI] 1.01-1.48, p = 0.0365; HR 1.60, 95% CI 1.32-1.91, p < 0.0001; HR 2.61, 95% CI 1.30-4.57, p = 0.0090, respectively). The 5-year RFS of the P-l and S-l groups was as poor as that of the P-h and S-h groups, respectively (HR 0.87, 95% CI 0.68-1.10, p = 0.25; HR 0.90, 95% CI 0.37-2.13, p = 0.81, respectively). The histopathological component of the S-l group was an independent factor affecting overall survival in multivariate analysis.

CONCLUSION

The long-term prognoses of the non-predominant poorly differentiated adenocarcinoma (PAC) groups were as poor as those of the predominant group. In particular, the histopathological component of the P-l and S-l groups could be classified into predominant PAC and SRCC subtypes for appropriate prognostic predictions.

The value of adjuvant chemotherapy in stage II/III colorectal signet ring cell carcinoma

This study aimed to assess the benefit of postoperative adjuvant chemotherapy in stage II–III colorectal signet ring cell carcinoma (SRCC). Qualified postoperative patients were extracted from Surveillance, Epidemiology, and End Results (SEER) database from 2004 until 2015. We collected 1675 patients in the research, and 936 patients were subjected to adjuvant chemotherapy group. The proportions of married status, male, rectal cancer, grade III/IV, AJCC stage III and radiotherapy were higher; While, the rates of white race, ≥ 65 years old and located in cecum–transverse colon were lower in patients of chemotherapy group compared to no chemotherapy group (all P < 0.05). K-M plots revealed significantly better OS of adjuvant chemotherapy group than no chemotherapy group (P < 0.001). Meanwhile, there was no significantly different in CSS between the two groups (P = 0.93). However, after adjusting for confounding factors by multivariable Cox regression analysis, receipt of postoperative chemotherapy was still associated with better CSS and OS (CSS: hazard ratio [HR] = 0.719, 95% CI 0.612–0.844, P < 0.001) ; (OS: HR = 0.618, 95% CI 0.537–0.713, P < 0.001). Patients with stage II/III colorectal SRCC could receive survival benefit from postoperative adjuvant chemotherapy.

Outcomes of Definitive Treatment of Signet Ring Cell Carcinoma of the Rectum: Is Minimal Invasive Surgery Detrimental in Signet Ring Rectal Cancers?

The outcome of surgery for signet ring adenocarcinoma of rectum is suboptimal with high predilection for locoregional and peritoneal metastases. Lack of intercellular adhesion due to focal loss of epithelial cell adhesion molecule (EpCAM) may account for this. In such patients, whether minimal invasive surgery carries a high risk of dissemination by pneumoperitoneum and tumor implantation remains uncertain. The aim of this study was to compare the outcomes of patients undergoing minimally invasive surgery (MIS) versus open surgery in patients with signet ring cell adenocarcinoma of rectum. A retrospective study was conducted at a tertiary care center over 3 years on 39 patients undergoing open surgery and 40 patients undergoing MIS diagnosed with signet ring cell carcinoma (SRCC) identified from our surgical database. Patient characteristics in terms of demographics, clinicoradiological staging, neoadjuvant therapy, and type of surgery with morbidity were compared in the two groups. Data on patients undergoing adjuvant therapy and 3 years disease-free survival (DFS) and overall survival (OS) were analyzed. Recurrence patterns in both groups were separately identified as locoregional, peritoneal, or systemic. The number of patients undergoing surgery in the two arms was 40 (MIS) and 39 (open). In the MIS arm, mean DFS was 29 months whereas in the open arm, it was 25.8 months. The mean OS was 33.65 months for the MIS arm and that for the open arm was 36.34 months. This retrospective study reveals no significant difference in outcomes of surgery for signet ring cell rectal cancers with either MIS or open approach.

Do microsatellite instability (MSI) and deficient mismatch repair (dMMR) affect the pathologic complete response (pCR) in patients with rectal cancer who received neoadjuvant treatment?

Recently, individualized approaches for the treatment of locally advanced rectal cancers (RC) have been introduced to determine the most beneficial one for boosting the tumor response and assessing the response more accurately. However, despite each patient and tumor have different molecular features, the studies at the molecular level are very limited. In this study, examining the clinical factors which are predictive of pathologic complete response (pCR), helping to determine a treatment program for the management of patients with locally advanced RC, and evaluating the relation between regression grade and MMR-MSI were aimed. 341 RC cases who had undergone surgery were included and divided into three groups according to their response to neoadjuvant treatment. The following parameters were analyzed for all patients: age at diagnosis, sex, tumor location, tumor differentiation, TNM stage, histological subtype, CEA (mean: < 5 ng/ml) level, lymphovascular-neural invasion, presence of mucinous subtype, grade, MMR, and MSI statuses. 147 patients (43.2%) had no response (group 1), 141 patients (41.3%) had an intermediate response (group 2), and 53 patients (15.5%) had a complete response (group 3). Neoadjuvant chemoradiotherapy was used in all of the patients with the same protocol. Multivariate analysis revealed that clinical T stage (p: 0.099) and MMR (p: 0.048) were the parameters which were significantly associated with pCR. Since MMR and MSI statuses were found to affect pCR, more careful patient selection for "watch and wait" protocol and further studies on molecular structures of the tumors for individualized therapies are required.

Prognosis of three histological subtypes of colorectal adenocarcinoma: A retrospective analysis of 8005 Chinese patients

BACKGROUND AND OBJECTIVES

To evaluate the effect of the varied histological subtypes on clinical outcomes and to determine the prognostic implications of mucinous adenocarcinomas (MAC) and signet ring cell carcinomas (SRCC) compared with classic adenocarcinomas (AC).

METHODS

A total of 8005 patients, including 7502 AC, 428 MAC and 75 SRCC, who underwent definitive surgery between 2007 and 2015 at Fudan University Shanghai Cancer Center were remained for analysis in this study.

RESULTS

MAC and SRCC were more common in right-sided colon cancer, in males and in young patients, compared to AC; moreover, MAC and SRCC led to a higher probability to develop lymph node metastasis, lymphovascular invasion and perineural invasion. For survival outcomes, we found that the 5-year overall survival (OS) of SRCC was significantly lower than that of MAC and AC, while the 5-year OS of MAC is much lower than that of AC. However, in multivariable analysis, the difference in survival between SRCC, MAC and AC was no longer significant, especially when stratified by N stage.

CONCLUSIONS

MAC and SRCC are rare subtypes of colorectal cancer with a higher T stage, N stage as well as higher incidence of lymphovascular and nerve invasion. However, neither MAC nor SRCC was an independent predictor of decreased survival in multivariate analysis.

Clinical Significance of Signet-Ring-Cell Colorectal Cancer as a Prognostic Factor

Purpose

The aim of this study is to evaluate the prognosis for patients with a signet-ring-cell carcinoma (SRCC) who undergo curative surgery by comparing them to patients with an adenocarcinoma (ADC), excluding a mucinous ADC.

Methods

Between September 1994 and December 2013, 14,110 patients with colorectal cancer underwent surgery and among them, 12,631 patients were enrolled in this study. 71 patients with a SRCC and 12,570 patients with a ADC were identified. We analyzed the disease-free survival and the overall survival rates before and after a 1:2 propensity score matching and evaluated those rates after stage stratification.

Results

The median follow-up durations were 48.5 months for the SRC group and 48.6 months for the ADC group. The disease-free survival rates and the overall survival rates were significantly lower in the SRC group before and after propensity score matching (P < 0.001). After stratification by stage, no differences were observed between the SRC and the ADC groups for the disease-free survival (DFS) and the overall survival (OS) rates for patients with cancer in its early stages (P = 0.913 and P = 0.380 for the DFS and the OS, respectively, in stages 0 and I, and P = 0.223 and P = 0.991 for the DFS and the OS, respectively, in stage II), but those rates were significantly lower in the SRC group for cancer in its later stages (P < 0.001, respectively in stages III and IV).

Conclusion

For cancer in advanced stages, patients with a resectable colorectal SRCC had a poorer prognosis after propensity score matching than those with an ADC did. Therefore, more intensive surveillance and closer observation should be offered to such patients.

Prognosis and value of preoperative radiotherapy in locally advanced rectal signet-ring cell carcinoma

As well known, signet-ring cell carcinoma (SRCC) is a rare histological subtype of colorectal adenocarcinoma, which has been associated with poor prognosis and resistant to non-surgery therapy compared with common adenocarcinoma. In this study, we assessed the effect of preoperative radiotherapy (PRT) for locally advanced rectal SRCC in a large patient group from the Surveillance, Epidemiology, and End Results program (SEER, 1988–2011) database. SRCC was found in 0.9% (n = 622) rectal cancer (RC) patients in our study. In the PRT setting, SRCC had significantly worse cancer-specific survival than mucinous adenocarcinoma and nonmucinous adenocarcinoma patients (log-rank, P < 0.001). In terms of SRCC, stage III RC patients benefited from PRT (log-rank, P < 0.001) while stage II did not (P = 0.095). The multivariate Cox proportional hazard model showed that PRT was an independent benefit factor in stage III rectal SRCC patients (HR, 0.611; 95% CI, 0.407–0.919; P = 0.018). In conclusion, SRCC was an independent predictor of poor prognosis in stage III RC patients, but not in stage II. In the PRT setting of locally advanced RC, SRCC patients had significantly worse prognosis. PRT was an independent prognostic factor associated with improved survival in stage III rectal SRCC.

Gastrointestinal cancers in India: Treatment perspective

GI cancer is not one cancer but is a term for the group of cancers that affect the digestive system including gastric cancer (GC), colorectal cancer (CRC), hepatocellular carcinoma (HCC), esophageal cancer (EC), and pancreatic cancer (PC). Overall, the GI cancers are responsible for more cancers and more deaths from cancer than any other organ. 5 year survival of these cancers remains low compared to western world. Unlike the rest of the world where organ based specialities hepatobiliary, pancreatic, colorectal and esophagogastric exist, these cancers are managed in India by either a gastrointestinal surgeons, surgical oncologist, or a general surgeon with varying outcomes. The aim of this review was to collate data on GI cancers in indian continent. In colorectal cancers, data from tertiary care centres identifies the unique problem of mucinous and signet colorectal cancer. Results of rectal cancer resection in terms of technique (intersphincteric resection, extralevator aper, minimal invasive approach) to be comparable with world literature. However long term outcome and data regarding colon cancers and nationally is needed. Gastric cancer at presentation are advanced and in surgically resected patients, there is need for a trial to compare chemoradiation vs chemotherapy alone to prevent loco regional recurrence. Data on minimal invasive gastric cancer surgery may be sparse for the same reason. Theree is a lot of data on surgical techniques and perioperatve outcomes in pancreatic cancer. There is a high volume of locally advanced gallbladder cancers with efforts on to decide whether neoadjuvant chemotherapy or neoadjuvant chemoradiotherapy is better for down staging. Considering GI cancers, a heterogeneous disease with site specific treatment options and variable outcomes, the overall data and outcomes are extremely variable. Young patients with pathology unique to the Indian subcontinent (for example, signet ring rectal cancer, GBCs) need focussed attention. Solution for such pathology needs to come from the Indian continent itself. Joint efforts to improve outcomes for GI cancer can be integrated under the national cancer grid program.