Impact of lymph node retrieval on surgical outcomes in colorectal cancers.

BACKGROUND: Adequacy of lymph node sampling is fundamental to the accuracy of nodal status (N-status) assessment in colorectal cancers (CRCs). This study aimed to determine the minimum sampling number to achieve reliable prognosis and to look for any association between the positive lymph node ratio (LNR) and overall survival (OS). Pathological reports of 533 stages I-III CRC patients who underwent curative resection during the period from January 1998 to December 2007 were retrospectively reviewed with regard to the number of lymph nodes obtained for pathological diagnosis (nLN) and number of positive nodes. RESULTS: The median nLN was 10 nodes and the mean number of positive nodes was 1.7 nodes. On the N-status attribution plot, the cut-off point where the converging curves turned parallel was at 12 nodes. This cut-off was supported by the significant difference in OS between cases with nLN ≥ 12 (5-year OS 73.0%) and those with nLN < 12 (5-year OS 62.7%), (P-value < 0.01). Multivariate analysis showed that both nLN-12 and LNR were independent factors predicting survival probability. CONCLUSION: Our data emphasize the importance of lymph node harvesting during the surgical resection of CRCs. In addition, LNR is a strong independent factor associated with CRC survival.

Survival analysis of colorectal cancer patients in a Thai hospital-based cancer registry.

Background: The study aimed to assess the overall and stage-specific colorectal cancer (CRC) survival and to identify the prognostic factors for survival among Thai patients.Research design and methods: The retrospective data of CRC patients from a university hospital-based cancer registry from 2001 to 2014 were used to estimate five-year overall survival (OS). Kaplan-Meier method and log-rank tests were used to assess the differences in five-year OS by age at diagnosis, diagnostic period, tumor site, stage at diagnosis and treatment modalities. A multivariate Cox's proportional hazard model was used to identify independent prognostic factors for the OS.Results: A total of 1,507 (48%) colon and 1,648 (52%) rectal cancer patients were included. Five-year OS for CRC patients was 44%. It differed significantly by stage, age group, and treatment received. Stage at diagnosis, age group, diagnostic period, receiving surgical and chemotherapy treatments were prognostic factors for OS.Conclusions: An increasing trend in the number of CRC patients mostly at stage III and IV was found. Our results emphasized that an improvement in CRC survival could be achieved through the adoption of advanced cancer therapies, as well as improved access to quality diagnosis and timely treatment.

WT1 expression as an independent marker of poor prognosis in colorectal cancers.

WT1 has been proven to be a prognostic marker and molecular target in various human cancers. In this study, we aimed to investigate the prognostic role of WT1 in colorectal cancers (CRCs). Archival tissue samples from 157 CRC cases who underwent curative surgery in our institute from February 1999 to May 2004 were subjected to WT1 expression studies using an immunohistochemistry technique. Number of positive staining per 500 tumor cells and staining intensities were analyzed against overall survival. Of 157 CRCs, 83 were colonic and 74 were rectal cancers. The mean follow-up period was 116 (range 77-145) months. Five-year and seven-year OS rates were 60.9% and 52.8%, respectively. WT1 immunostaining was positive in 143 cases (91%). The median number of positive cells was 120 (range 0-420). Univariate analysis by Log-rank test showed that AJCC stage, tumor site (rectal cancer), number of positive cells > 120 and high staining intensity (score ++/+++) were significantly associated with poorer survival (p-value < 0.01). Five-year survival rates in cases with positive cells of ⩽ 120 cells and > 120 cells were 72.2% and 49.4%, respectively. Five-year survival in cases with staining intensity of ++ or more was 45.3%, compared with 69% in cases with intensity of less than ++. Multivariate regression analysis demonstrated that the staining intensity, high tumor stage and rectal site were independent factors indicating poorer survival. Our findings indicate that WT1 expression is a marker of poor prognosis in CRCs, independent of AJCC staging.