Neoadjuvant and Adjuvant Chemotherapeutic Strategy of Colorectal Mixed Adeno-Neuroendocrine Carcinomas

Mixed neuroendocrine non-neuroendocrine neoplasms in gastroenteropancreatic tract

Mixed neuroendocrine non-neuroendocrine neoplasms (MiNENs) are a heterogeneous group of malignant neoplasms that can settle in the gastroenteropancreatic tract. They are composed of a neuroendocrine (NE) and a non-NE component in at least 30% of each tumour. The non-NE component can include different histological combinations of glandular, squamous, mucinous and sarcomatoid phenotypes, and one or both of the components can be low-or high grade malignant. Recent changes in the nomenclature of these neoplasms might lead to great deal of confusion, and the lack of specific clinical trials is the main reason why their management is difficult. The review aims to clarify the definition of MiNEN and analyze available evidence about their diagnosis and treatment options according to their location and extension through careful analysis of the available data. It would be important to reach a general consensus on their diagnosis in order to construct a classification that remains stable over time and facilitates the design of clinical trials that, due to their low incidence, will require long recruitment periods.

Comparison of survival outcomes and survival prediction in patients with primary colorectal MANEC and primary colorectal SRCC: a population-based propensity-score matching study

PURPOSE

Primary mixed adeno-neuroendocrine carcinoma (MANEC) and primary signet-ring cell cancer (SRCC) are two rare but highly malignant tumors in colorectal cancer. Therefore, we attempted to compare the tumors' survival outcomes, identify risk factors, and ultimately evaluate the prognosis by developing a nomogram.

METHODS

We identified 755 MANEC and 5836 SRCC patients of colorectal cancer. PSM was used to balance the influence of baseline clinical and pathological differences. Kaplan-Meier method was used to compare the prognosis of different pathological grades and AJCC stages. Cox proportional hazards model was used to identify potential prognostic factors for the two groups. Finally, we developed a nomogram and evaluated the feasibility of the model.

RESULTS

After PSM, the median OS and CSS of MANEC patients were significantly better than those of SRCC patients in stage III-IV (P < 0.001) but similar in stage I-II. The median OS and CSS of MANEC patients in each pathological grade were also greater than those of SRCC patients. Patients with MANEC and SRCC who underwent lymph node dissection in more than four areas had longer survival time. MANEC patients benefited from postoperative chemotherapy and radiotherapy; among SRCC patients, those who received preoperative and postoperative comprehensive chemotherapy and radiotherapy had benefits in OS and CSS.

CONCLUSION

Both MANEC and SRCC are often diagnosed in advanced stages, highlighting the importance of early screening. Despite the better prognosis of MANEC compared to SRCC, both types of patients require the formulation of personalized treatment strategies based on different risk factors combined with column charts.