Mismatch Repair Status Correlates with Survival in Young Adults with Metastatic Colorectal Cancer

BACKGROUND

Young adults with metastatic colorectal cancer (mCRC) may have higher rates of deficient mismatch repair (dMMR) than older patients. This study sought to assess patterns of MMR-testing and survival among young adult mCRC patients in the National Cancer Database (NCDB), hypothesizing that dMMR correlates with worse survival than in MMR-proficient (pMMR) patients.

METHODS

Stage-IV colorectal cancers were identified in NCDB (2010-2016). Demographic and clinical features were compared between younger (age ≤ 30) and older mCRC patients and tested for association with overall survival. Stage-IV disease without other recorded metastatic sites defined peritoneal metastasis (PM). Fisher-exact tests compared proportions and Cox models tested association with overall survival.

RESULTS

Of 124,587 stage-IV colorectal cancers, 1,123 (0.9%) were in young patients. Young patients were more likely to have mucinous histology, high-grade, rectal primaries, and isolated peritoneal metastases (P < 0.001). Younger patients more often had MMR-testing (29.1 versus 16.6%), with dMMR found at similar rates in young and older patients (21.7 versus 17.1% of those tested, P= 0.4). Despite higher rates of adverse prognostic features, younger patients had better survival (median 20.7 versus 14.8 months, P < 0.001). In MMR-tested patients, dMMR correlated with higher mortality risk compared to pMMR (median 16.6 months versus 25.5 months, P = 0.01). On multivariable analysis, grade and MMR-status remained independently associated with survival.

CONCLUSIONS

Median survival was worse with dMMR by 8.9 months compared to pMMR in young adults with mCRC. Despite higher rates of familial syndromes in young patients and recommendations for universal MMR-testing, over 70% of young mCRC patients had no MMR-status recorded.

Inflammatory bowel disease drastically affects the prognosis of patients treated for peritoneal metastases with combined cytoreductive surgery and hyperthermic intraperitoneal chemotherapy: A multicenter study

BACKGROUND

Complete cytoreductive surgery (CCRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a validated treatment in selected patients with peritoneal metastases (PM) of intestinal origin. There is an increased risk of Colorectal Cancer (CRC) and Small Bowel Adenocarcinoma (SBA) in Inflammatory Bowel Disease (IBD). The feasibility and benefit of that surgical approach in IBD patients is unknown.

METHODS

IBD patients with operated PM complicating CRC or SBA were extracted from a French national multicenter prospective database of patients who underwent surgery for PM in HIPEC expert centers from 1995 to 2016. IBD patients who underwent CCRS plus HIPEC were compared with a cohort of 234 patients who had the same surgery for sporadic colon cancer.

RESULTS

14 patients (male 57%, median age 40 years, 12 Crohn's disease) with CRC (n = 7) and SBA (n = 7) were included. CCRS followed by HIPEC (oxaliplatin 72.7%) was performed in 11 cases (median peritoneal cancer index 7; range 1-30). The control group had the same characteristics except an older age at HIPEC (56.52 vs 45.74; p = 0.003). Overall survival (HR = 4.47; 90% CI, 1.91 to 10.49), Relapse Free Survival (HR = 2.31; 90% CI, 1.17 to 4.56) and Peritoneal Recurrence Free Survival (HR = 3.30; 90% CI, 1.59 to 6.85) were significantly lower in IBD patients. Six of the 11 patients presented major surgical morbidity with no impact on post-operative treatment.

CONCLUSION

CCRS followed by HIPEC is less effective in IBD patients with resectable PM complicating CRC or SBA. More careful selection of those patients is needed.

Cytoreductive Surgery plus HIPEC for Peritoneal Metastases from Colorectal Cancer

Occurring either synchronously or metachronously to the primary tumor, peritoneal metastases (PM) are diagnosed in 8 to 20 % of the patients with colorectal cancer (CRC). Prognosis of these patients appears to be worse than those with other sites of metastases. While systemic therapy has shown significant prolongation of survival in patients with stage IV colorectal cancer, the outcomes in the subset of patients with PM has been much inferior. Over the last 2 decades, cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) have been effective in substantially prolonging survival in patients with colorectal PM and have the potential to cure certain patients as well. This article reviews the current evidence for CRS and HIPEC to treat colorectal PM as well as future research going on in this form of locoregional treatment.

The Initial Indian Experience with Cytoreductive Surgery and HIPEC in the Treatment of Peritoneal Metastases

Worldwide, cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) has been used for nearly 3 decades to treat peritoneal metastases (PM), improve quality of life, and prolong survival substantially in selected patients. In India, the use of the combined modality of treatment dates back a decade with majority of the efforts taking place within the last 5 years. The first PSOGI workshop (India) held in April 2015, at Bangalore, India offered an opportunity for Indian surgeons performing CRS and HIPEC to share their experience. To study the methodologies of CRS and HIPEC (hospital set up, equipment, training and surgical background) as well as the outcomes in terms of perioperative morbidity and mortality and short and long term survival of patients treated in India, Indian surgeons who had treated at least 10 patients with this combined modality were invited to present their experience. Data collection was retrospective. Analysis of the pooled data was carried out. Eight surgeons treated 384 patients with CRS and HIPEC over a period of 10 years. The commonest primary sites were ovary (as first line therapy n = 124), followed by appendix, including pseudomyxoma peritonei (n = 99), colorectum (n = 77), recurrent ovary (as second line therapy, n = 33), stomach (n = 15), primary peritoneal cancer (n = 10), peritoneal mesothelioma (n = 9) and rare tumors in 17 patients. The weighted mean PCI for all 384 patients was 18.25. 349/384 patients (90.88 %) had a complete cytoreduction (completeness of cytoreduction score of CC-0/1). Grade 3-5 complications developed in 108 patients (27.34 %) and 30 day mortality occurred in 28 (7.29 %) patients. This study showed that CRS and HIPEC can be performed with an acceptable morbidity and mortality in Indian patients. Most of the surgeons are on the learning curve and further improvement in these outcomes is expected over a period of time. Pooling of data related to both common and rare peritoneal cancers would be useful in knowing the disease behavior, response to treatment and outcomes in Indian patients. The 2015 PSOGI meeting provided a unique platform for data presentation with feedback from international experts in the field of peritoneal surface oncology. Future meetings are planned to expand the evaluation of Indian data and progress.