Prognostic impact of the number of lymph nodes examined in different stages of colorectal mucinous adenocarcinoma

Abstract

BackgroundMucinous adenocarcinoma (MC) is a special kind of colorectal adenocarcinoma that occurs more frequently in young patients and females, but the prognostic effect of lymph nodes in MC patients is unclear. This population-based study was conducted to analyze the prognostic value of the number of lymph nodes examined in different stages of colorectal MC.MethodsWe included 17,001 MC patients from the Surveillance, Epidemiology, and End Results program database between 2003 and 2013, of which 12,812 (75%) had >12 lymph nodes examined.ResultsCompared to the group with insufficient lymph nodes examined, patients with more lymph nodes (>12) examined tended to come from east and central America, were more frequently female and young, were diagnosed after 2008, had larger-sized tumors of less differentiated grade and in later stages, had not received radiation therapy and had more positive nodal status. Patients with more lymph nodes (>12) examined demonstrated significantly better survival than those with insufficient lymph nodes examined only in stages II and III (stage II: overall, P<0.001; cancer-specific, P<0.001; stage III: overall, P=0.093; cancer-specific, P=0.032), even though the overall (P<0.001) and cancer-specific survival (P<0.001) showed significant differences between the two groups. Both univariate (overall, HR=0.739, 95% CI=0.703–0.777, P<0.001; cancer-specific, HR=0.742, 95% CI=0.698–0.788, P<0.001) and multivariate (overall, HR=0.601, 95% CI=0.537–0.673, P<0.001; cancer-specific, HR=0.582, 95% CI=0.511–0.664, P<0.001) Cox proportional hazards models verified the association between >12 lymph nodes examined and better survival.ConclusionMore number of lymph nodes (.12) examined significantly increased the survival probability of MC patients in stages II and III, but had no significant influence on patients in stages I and IV, indicating the effect of number of lymph nodes examined was a stage-dependent prognostic factor in clinical utility.

Tumor sidedness influences prognostic impact of lymph node metastasis in colon cancer patients undergoing curative surgery

“…The number of LNs examined and LN ratios are two variables frequently used to assess the impact of lymph node metastasis on postoperative survival in colon cancer 20–22,27–29 . It was suggested that at least 12 LNs should be examined pathologically to determine the absence of lymph node metastasis in colon cancer patients 17–19 .…”

“…However, the relevant debate has never ended because optimal other than 12 have been implied, such as 20 23 , 21 24 , and 22 25 . Similar to tumor sidedness, the prognostic value of the number of LNs examined varied depending on stages of colon cancer 21,22,26 . In addition, the prognostic effect of LN ratio, defined as the ratio of the number of positive LNs to the total number of LNs examined, has been demonstrated in stage II and III colon cancer patients 27,28 .…”

“…The extent to which lymph node metastasis affects colon cancer prognosis has been widely investigated for decades. Several lines of evidence suggested that a minimum of 12 lymph nodes (LNs) should be examined pathologically for adequate N staging in colon cancer patients 17–19 , and that the number of LNs examined (≥12) was significantly associated with OS, DSF, and CSS in colon cancer 20–22 . However, the relevant debate has never ended because optimal other than 12 have been implied, such as 20 23 , 21 24 , and 22 25 .…”

Incidence of Colorectal carcinoma in Young Population of Islamabad

“…Colonoscopy is the best investigation to detect the early neoplastic changes and even if a polyp is seen on colonoscopy it is removed at the same time [26,27]. Unfortunately in Pakistan screening is not done as a routine investigation, particularly in rural areas because of illiteracy and lack of access to health care centre and even in urban areas due to lack of awareness patients reach the health care centres in late stages [28][29][30][31][32][33][34][35][36][37][38][39]. Even when patient go to a hospital with symptoms of bowel disease colonoscopy is not done as a screening test.…”

Mucinous adenocarcinoma: A unique clinicopathological subtype in colorectal cancer

“…Studies have also demonstrated that higher age (> 65 years), tumor grades including moderately, poorly, and undifferentiated tumors, tumor location in the rectum, preoperative CEA level (> 5 ng/mL), higher pathological T or N stage, intestinal obstruction, and perineural infiltration were all significantly associated with poor OS in MAC[ 7 , 120 ]. A greater number of lymph nodes examined (no fewer than 12) significantly increased OS (HR = 0.601, 95%CI: 0.537-0.673, P < 0.001) and CSS (HR = 0.582, 95%CI: 0.511 to -0.664, P < 0.001) in patients with colorectal MAC[ 120 ]. BRAF mutations were significantly associated with CRC-specific mortality (multivariate HR = 1.64, 95%CI: 1.18-2.27, P = 0.003), while MSI-H was associated with a statistically significant reduction in CRC-specific mortality (multivariate HR = 0.28, 95%CI: 0.17-0.46, P < 0.001).…”