Nomogram for predicting the overall survival of underweight patients with colorectal cancer: a clinical study.

BACKGROUND: An underweight individual is defined as one whose Body Mass Index (BMI) is < 18.5 kg/m2. Currently, the prognosis in patients with colorectal cancer (CRC) who are also underweight is unclear. METHODS: Information on South Korean patients who underwent curative resection for CRC without distant metastasis was collected from health insurance registry data between January 2014 and December 2016. We compared the overall survival (OS) of underweight and non-underweight (BMI ≥ 18.5 kg/m2) patients after adjusting for confounders using propensity score matching. A nomogram to predict OS in the underweight group was constructed using the significant risk factors identified in multivariate analysis. The predictive and discriminative capabilities of the nomogram for predicting 3- and 5-year OS in the underweight group were validated and compared with those of the tumor, node, and metastasis (TNM) staging system in the training and validation sets. RESULTS: A total of 23,803 (93.6%) and 1,644 (6.4%) patients were assigned to the non-underweight and underweight groups, respectively. OS was significantly worse in the underweight group than in the non-underweight group for each pathological stage (non-underweight vs. underweight: stage I, 90.1% vs. 77.1%; stage IIA, 85.3% vs. 67.3%; stage IIB/C, 74.9% vs. 52.1%; and stage III, 73.2% vs. 59.4%, P < 0.001). The calibration plots demonstrated that the nomogram exhibited satisfactory consistency with the actual results. The concordance index (C-index) and area under the receiver operating characteristic curve (AUC) of the nomogram exhibited better discriminatory capability than those of the TNM staging system (C-index, nomogram versus TNM staging system: training set, 0.713 versus 0.564, P < 0.001; validation set, 0.691 versus 0.548, P < 0.001; AUC for 3- and 5- year OS, nomogram versus TNM staging system: training set, 0.748 and 0.741 versus 0.610 and 0.601; validation set, 0.715 and 0.753 versus 0.586 and 0.579, respectively). CONCLUSIONS: Underweight patients had worse OS than non-underweight patients for all stages of CRC. Our nomogram can guide prognostic predictions and the treatment plan for underweight patients with CRC.

Long-term oncologic outcome of D3 lymph node dissection for clinical stage 2/3 right-sided colon cancer.

PURPOSE: To investigate oncologic outcomes including overall survival and disease-free survival depending on the extent of lymphadenectomy (D3 versus D2) by comparing D3 and D2 lymphadenectomy in patients with clinical stage 2/3 right colon cancer. METHODS: Consecutive series of patients who underwent radical resection for right colon cancer at our three hospitals between January 2015 and June 2018 were retrospectively analyzed. Study cohorts were divided into two groups: D3 group and D2 group. Oncologic, pathologic, and perioperative outcomes of the two groups were compared. RESULTS: A total of 295 patients (167 in the D2 group and 128 in the D3 group) were included in this study. Patients' characteristics showed no significant difference between the two groups. The median number of harvested lymph nodes was significantly higher in the D3 group than in the D2 group. The rate of complications was not significantly different between the two groups except for chyle leakage, which was more frequent in the D3 group. Five-year disease-free survival was 90.2% (95% CI: 84.8-95.9%) in the D3 group, which was significantly (p = 0.028) higher than that (80.5%, 95% CI: 74-87.5%) in the D2 group. There was no significant difference in overall survival between the two groups. CONCLUSION: Our results indicate that D3 lymphadenectomy is associated with more favorable 5-year disease-free survival than D2 lymphadenectomy for patients with stage 2/3 right-sided colon cancer. D3 lymphadenectomy might improve oncologic outcomes in consideration of the recurrence rate.

Prognosis and Sensitivity of Adjuvant Chemotherapy in Mucinous Colorectal Adenocarcinoma without Distant Metastasis.

In colorectal cancer, whereas mucinous adenocarcinoma (MAC) has several poor clinical prognostic factors compared to adenocarcinoma (AC), the prognosis of MAC remains controversial. We evaluated the prognosis of MAC without distant metastasis and the effects of adjuvant chemotherapy using health insurance registry data managed by South Korea. Patients with colorectal cancer between January 2014 and December 2016 were included (AC, 22,050 [96.8%]; MAC, 729 [3.2%]). We observed no difference in overall survival (OS) between AC and MAC in stages I and II. However, MAC showed a worse OS than AC in stage III disease, especially in patients administered chemotherapy (p < 0.001). These findings persisted after propensity score matching of clinical characteristics between AC and MAC. In addition, transcriptome analysis of The Cancer Genome Atlas (TCGA) data showed increased chemoresistance-associated pathways in MAC compared to AC. In consensus molecular subtypes (CMS) classification, unlike in AC, CMSs 1, 3, and 4 comprised most of MAC and the proportions of CMSs 3 and 4 increased with stage progression. These results suggest clues to overcome resistance to chemotherapy and develop targeted treatments in MAC.

Treatment outcomes of patients with involved resection margin after rectal cancer surgery: A nationwide population-based cohort study in South Korea.

BACKGROUND: The involvement of resection margins after rectal cancer surgery by malignant tumors is a negative prognostic factor. Therefore, it is important to analyze treatment outcomes and establish adjuvant therapy. METHODS: The Health Insurance Review and Assessment Service collects data from medical institutions in South Korea. We reviewed the database of this prospectively collected cohort for patients who underwent curative resection for rectal cancer. RESULTS: Of the 5,620 patients, 113 (2.0%) were diagnosed with resection margin involvement after surgery. The resection margins of patients with mid-rectal cancer, pathologic stage III, mucinous/signet ring cell carcinoma, and undergoing emergency surgery were more frequently involved. Neoadjuvant chemoradiotherapy was a significant preventive factor for resection margin involvement (odds ratio = 0.53; 95% confidence interval [CI], 0.32-0.87; p = 0.012). The OS of patients with adjuvant treatment was better than that of patients without adjuvant treatment (5-year overall survival [OS]: 62.8% vs. 46.3%, p = 0.02). The administration of chemoradiotherapy was also significantly associated with better OS (hazard ratio = 0.36; 95% CI, 0.17-0.77; p = 0.009). CONCLUSION: Efforts to acquire wider resection margins are necessary for patients with mid-rectal cancer, pathologic stage III, mucinous/signet ring cell carcinoma, and emergency surgery. Neoadjuvant chemoradiotherapy was a significant preventive factor for involved resection margin. Patients with resection margin involvement showed better OS after adjuvant treatment than those without adjuvant treatment. The adjuvant chemoradiotherapy was helpful to prevent the worse prognosis of these patients.

Clinical characteristics of rectal cancer patients with neoadjuvant chemoradiotherapy: a nationwide population-based cohort study in South Korea.

PURPOSE: Neoadjuvant chemoradiotherapy has been accepted as a standard treatment for stage II-III rectal cancer. This study aimed to evaluate the clinical characteristics of patients who underwent neoadjuvant chemoradiotherapy for rectal cancer and effects on overall survival (OS) of neoadjuvant chemoradiotherapy in South Korea. METHODS: Patients who underwent curative resection for rectal cancer from 2014 to 2016 were retrospectively reviewed from the database of the National Quality Assessment program in South Korea. Patients were categorized into the upfront surgery group and neoadjuvant chemoradiotherapy group. We evaluated factors associated with the administration of neoadjuvant chemoradiotherapy and its effects on OS. Inverse probability of treatment weighting was performed to account for baseline differences between subgroups. RESULTS: A total of 6,141 patients were categorized into the upfront surgery group (n = 4,237) and neoadjuvant chemoradiotherapy group (n = 1,904). The neoadjuvant chemoradiotherapy was more frequently administered to male, midrectal cancer, and younger patients. In the neoadjuvant chemoradiotherapy group, old age, underweight, and pathologic stage were significant risk factors of OS, and male sex, the level of tumor and clinical stages were not associated with OS. After adjustment, the OS of the neoadjuvant chemoradiotherapy group followed the OS of the upfront surgery group of the same pathologic stage. CONCLUSION: Male sex and the level of tumor were not related to the OS of rectal cancer patients with neoadjuvant chemoradiotherapy. The OS of patients who underwent neoadjuvant chemoradiotherapy was decided by their pathologic stages regardless of clinical stages.

Effects of the proximity of metastasis to the central vessels of the liver on surgical outcomes and survival in colorectal cancer with liver metastasis.

BACKGROUND: Resectability of liver metastasis is important to establish a treatment strategy for patients with colorectal cancer. We aimed to evaluate the effect of the distance from metastasis to the centre of the liver on surgical outcomes and survival after hepatectomy. METHODS: The clinical data of a total of 155 patients who underwent hepatectomy for colorectal cancer with liver metastasis were retrospectively reviewed. We measured the minimal length from metastasis to the bifurcation of the portal vein at the primary branch of the Glissonean tree and defined it as 'centrality'. The postoperative outcomes and survival among the patients were then analysed. RESULTS: Anatomic resections were more frequently performed, and the operative time was longer in the patients with high centrality (≤1.5 cm) than in the patients with low centrality (>1.5 cm). A size of ≥5 cm for the largest lesion, a number of lesions of ≥3 and centrality of ≤1.5 cm were found to be the independent risk factors of a positive resection margin after hepatectomy. The patients with high centrality showed worse recurrence-free survival than those with low centrality; however, there was no significant difference found in the overall survival. In the multivariate analysis, high centrality was not found to be associated with worse recurrence-free and overall survival. CONCLUSION: Centrality significantly affected the surgical outcomes and treatment strategy for liver metastasis but did not influence the survival of the patients with colorectal cancer. Active efforts through surgical resections are important to treat liver metastasis of high centrality.