Validation of a new classification system for curatively resected colorectal adenocarcinoma

Abstract

BACKGROUND The parameters within which colorectal adenocarcinoma is currently staged are often insufficient for decisions regarding therapy after potentially curative surgery. Consequently, oncologists make frequent use of additional prognostic indicators when assessing individual prognosis and selecting patients for adjuvant systemic treatment. Follow‐up programs are generally uniform for all patients, regardless of disease stage and prognosis. As a result, patients with a favorable prognosis are needlessly subjected to stressful, costly follow‐up too early and too frequently. This study was conducted to validate a new classification system that is a superior predictor of individual prognosis following curative surgery and may serve as a guide for personalized, cost‐effective postoperative management and follow‐up. METHODS A total of 231 American colorectal carcinoma patients who underwent curative resection were retrospectively staged according to a new classification (containing 4 stage‐groups) for curatively resected colorectal adenocarcinoma. This classification is based on statistical analysis of the impact on prognosis of numerous characteristics of 363 consecutive Israeli colorectal carcinoma patients who underwent curative resection. All the patients in both cohorts had had surgery at least 5 years previously. The new classification is based on three histologic variables (venous invasion, depth of primary tumor penetration, and regional lymph node status) and a scoring system that correlates higher numeric score with worse prognosis. In both cohorts, the new classification was compared with the Dukes, Astler–Coller, and TNM staging systems for patient distribution and survival (both disease free and cancer‐related survival). RESULTS In both cohorts, the 4 stage‐groups of the new classification differed significantly in both the rate of and the time to first recurrence and cancer‐related death, with progression from Group 4 to Group 1. Groups of high risk lymph node negative patients were defined, and lymph node positive patients were subdivided according to prognosis. It is suggested that, by using this new classification as a guide, selection for adjuvant systemic treatment may be refined, and postoperative follow‐up may be personalized and therefore more cost‐effective. CONCLUSIONS The new classification for curatively resected colorectal adenocarcinoma, based on an analysis of the Israeli cohort and validated in the American cohort, is superior to the Dukes, Astler–Coller, and TNM staging systems as a predictor of individual prognosis, most probably because it incorporates the microscopic forerunner of distant, hematogenous spread (i.e., venous invasion) with the locoregional parameters of extent of disease (i.e., T and N values). It is suggested that the new classification may serve as a guide for more refined selection of patients for adjuvant systemic treatment and for individualized and more cost‐effective postoperative follow‐up. The new classification is simple and easy to use, requires...

Conclusions from a study of venous invasion in stage IV colorectal adenocarcinoma

“…23 Dirschmid et al, 20 Horn et al, 16 17 and Blumberg and colleagues 24 recommend considering venous invasion as an indicator for the administration of systemic adjuvant treatment. Based on our study of 231 consecutive curatively resected patients with CRC, 22 in which we found that distant metastases developed in 50% of the venous invasion positive patients, and in only 36% of the node-positive patients, we are inclined to agree with these authors.…”

“…Venous invasion may be used to enhance the power of existing staging systems as predictors of individual prognosis by subdividing stages according to the presence or absence of venous invasion, 21 or it may be combined with other variables to form a completely new classification of CRC. 22 According to the National Institutes of Health consensus statement on adjuvant treatment of CRC, regional lymph node status is currently the main indicator for the administration of systemic adjuvant treatment. 23 Dirschmid et al, 20 Horn et al, 16 17 and Blumberg and colleagues 24 recommend considering venous invasion as an indicator for the administration of systemic adjuvant treatment.…”

Tumor deposits are encountered in advanced colorectal cancer and other adenocarcinomas: an expanded classification with implications for colorectal cancer staging system including a unifying concept of in-transit metastases

“…8 As far as vascular invasion is concerned, it is still unclear whether different types of vascular invasion (lymphatic or venous) are prognostically relevant as independent factors. 9 A proposal to include venous invasion among stage influencing factors in colorectal cancer has already been made [10][11][12] and it is still being debated as to whether this finding per se may have clinical implications on tumor staging. 13 In this regard, we believe that grouping tumor deposits with other types of vascular invasion will account for the prognostic heterogeneity of these particular lesions.…”

Cetuximab in first line treatment of metastatic colorectal cancer

“…La recidiva dopo l'intervento chirurgico spesso rappresenta una rilevante causa di morte. La prognosi è correlata al grado di coinvolgimento della parete viscerale e all'interessamento dei linfonodi [34], altri fattori prognostici rilevanti sono il grading, l'invasione vascolare [35], l'invasione perineurale, il numero dei linfonodi interessati. I più recenti fattori prognostici sono le mutazioni genetiche p53, KRAS, EGFR, l'indice di proliferazione.…”

“…I più recenti fattori prognostici sono le mutazioni genetiche p53, KRAS, EGFR, l'indice di proliferazione. L'occlusione e la perforazione intestinale sono indici prognostici negativi [35], così come livelli sierici pre-trattamento dell'antigene carcino-embrionario (CEA) e dell'antigene carboidratico 19-9 (CA 19-9) [36]. Tra i fattori correlati al paziente, il perfomance status (ovvero le condizioni generali) in- fluenzano in maniera importante il risultato del trattamento terapeutico [37], con tassi di risposta ai comuni regimi chemioterapici del 30-60% nei pazienti con perfomance status di 0, del 10-30% e 0-10% nei casi di performance status di 1 e 2, rispettivamente.…”