Survival difference between mucinous vs. non-mucinous colorectal cancer following cytoreductive surgery and intraperitoneal chemotherapy

The Effect of the Mucinous Component Presence on the Clinical Outcomes of Colorectal Cancer

Background. The effect of colorectal cancer (CRC) histological subtypes on the prognosis is still a controversial issue. We aimed to compare clinical findings, histopathologic data, and survival outcomes in CRC patients with classical and mucinous subtypes. Methods. Patients who were operated on for CRC between 2010 and 2017 were included in the study. Patients were classified into two groups according to the presence of a mucinous component: mucinous adenocarcinoma (MAC) - mucinous component > 50% and classical adenocarcinoma (CAC). Clinical and histopathologic findings, recurrence, metastasis, and survival rates were compared. Results. Data of the 484 CRC patients were documented. Sixty-nine patients (14.3%) were in the MAC group and 415 (85.7%) patients were in the CAC group. The mean age of patients with MAC and CAC was 63.4 ± 13.5 and 68.5 ± 12.7 years, respectively (p = 0.002). Proximal colon localization was found in 30 (43.5%) MAC patients and 123 (29.6%) CAC patients (p = 0.029). The number of patients with metastatic lymph nodes was higher in the MAC group (58% vs. 41.2%, p = 0.03). Nevertheless, there was no significant difference between the CAC and MAC groups in terms of disease-free survival (63.1% vs. 69.6%, p = 0.37) and disease-related mortality (23.6% vs. 23.2%, p = 0.94) over the follow-up period. Multivariate analysis showed that the presence of perineural invasion, patient’s age, and disease stage were associated with mortality in CRC patients. Conclusions. MACs occurred at a younger age than CACs and were more likely localized in the proximal colon as compared to CACs. Despite increased lymph node metastasis in MAC patients, no statistical significance was detected in overall survival or disease-free survival. Multivariate analysis revealed that age, perineural invasion, and disease stage were relevant to mortality in CRC patients.

Patients with Metachronous Peritoneal Metastatic Mucinous Colorectal Adenocarcinoma Benefit More from Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) than Their Synchronous Counterparts

Background: Mucinous adenocarcinoma is a frequent subtype in colorectal cancer (CRC). A higher initial T-stage, poorer differentiation, worse response to anti-tumor therapies, and shorter survival are characteristic of mucinous CRC. Moreover, the therapeutic benefit of cytoreductive surgery with hyperthermic intraperitoneal chemotherapy (CRS + HIPEC) in mucinous CRC has not been significantly investigated. Methods: A retrospective analysis of 218 CRC patients with synchronous or metachronous peritoneal metastases was conducted. Results: 129 and 89 patients had synchronous and metachronous metastases, and 36 (27.8%) and 22 (24.8%) of these were mucinous CRC, respectively. Mucinous CRC was more frequent in the proximal colon, with a higher T-stage and N-stage and with an average peritoneal carcinomatosis index that was 2 values higher. Disease-specific survival was significantly worse in the synchronous mucinous group (median survival: 22.4 months vs. 36.3 months, p = 0.0229). In contrast, no such difference was observed in the metachronous cohort (32.6 months vs. 34.4 months, p = 0.6490). Conclusions: In the case of synchronous peritoneal metastases originating from mucinous CRC, the positive effect of CRS+HIPEC cannot be verified, and the added value of this highly invasive treatment is therefore somewhat questioned. However, CRS + HIPEC is recommended for metachronous metastases, since no difference between the two CRC-subtypes could be verified.

Chasing Rainbows? the Possibility of "Cure" in Patients with Colorectal Peritoneal Metastases Undergoing Cytoreductive Surgery and HIPEC-a Retrospective Study by INDEPSO

Cytoreductive surgery (CRS) and HIPEC results in a median disease-free survival (DFS) of 12-15 months, overall survival (OS) of 23-63 months, and cure in around 15% of patients with colorectal peritoneal metastases (CPM). The wide variation in OS may largely be attributed to different criteria for patient selection employed by different investigators. To evaluate outcomes of CRS and HIPEC for CPM in patients enrolled in the Indian HIPEC registry. A retrospective analysis of patients enrolled in the registry since its inception in March 2016 was performed. The impact of various prognostic factors on DFS and OS was evaluated. From Jan 2013 to Dec 2017, 68 patients underwent CRS with HIPEC at six Indian centers. The median PCI was nine [range 3-35]. Twenty-two (32.3%) had mucinous tumors. A CC-0 resection was performed in 53 (77.9%) and CC-1 in 14 (20.5%). The median DFS was 12 months [95% CI 11.037-12.963 months] and the median OS 25 months [95% CI 18.718-31.282]. The DFS was inferior in patients with right upper quadrant involvement (p = 0.02) and 90-day major morbidity (p = 0.002) and OS inferior in those with 90-day major morbidity (p < 0.001) and mucinous tumors with a PCI > 20. The DFS compares well with results obtained by pioneering teams but we have no "cured" patients. Better patient selection and utilization of systemic therapies could in the future improve the OS. There is a compelling need to identify subgroups of CPM that benefit from the addition of HIPEC to CRS.