Colitis-Associated Colorectal Cancer Survival is Comparable to Sporadic Cases after Surgery: a Matched-Pair Analysis

BACKGROUND

Inflammatory bowel disease (IBD) confers an increased lifetime risk of colorectal cancer (CRC). The pathogenesis of colitis-associated CRC is considered distinct from sporadic CRC, but existing is mixed on long-term oncologic outcomes. This study aims to compare clinicopathological characteristics and survival between colitis-associated and sporadic CRC.

METHODS

Data was retrospectively extracted and analyzed from a single institutional database of patients with surgically resected CRC between 2004 and 2015. Patients with IBD were identified as having colitis-associated CRC. The remainder were classified as sporadic CRC. Propensity score matching was performed. Univariate and survival analyses were carried out to estimate the differences between the two groups.

RESULTS

Of 2275 patients included in this analysis, 65 carried a diagnosis of IBD (2.9%, 33 Crohn's disease, 29 ulcerative colitis, 3 indeterminate colitis). Average age at CRC diagnosis was 62 years for colitis-associated CRC and 65 for sporadic CRC. The final propensity score matched cohort consisted of 65 colitis-associated and 130 sporadic CRC cases. Patients with colitis-associated CRC were more likely to undergo total proctocolectomy (p < 0.01) and had higher incidence of locoregional recurrence (p = 0.026) compared to sporadic CRC patients. There were no significant differences in time to recurrence, tumor grade, extramural vascular invasion, perineural invasion, or rate of R0 resections. Overall survival and disease-free survival did not differ between groups. On multiple Cox regression, IBD diagnosis was not a significant predictor of survival.

CONCLUSIONS

Patients with colitis-associated CRC who undergo surgical resection have comparable overall and disease-free survival to patients with sporadic CRC.

Tumour genotypes account for survival differences in right- and left-sided colon cancers

AIM

We sought to identify genetic differences between right- and left-sided colon cancers and using these differences explain lower survival in right-sided cancers.

METHOD

A retrospective review of patients diagnosed with colon cancer was performed using The Cancer Genome Atlas, a cancer genetics registry with patient and tumour data from 20 North American institutions. The primary outcome was 5-year overall survival. Predictors for survival were identified using directed acyclic graphs and Cox proportional hazards models.

RESULTS

A total of 206 right- and 214 left-sided colon cancer patients with 84 recorded deaths were identified. The frequency of mutated alleles differed significantly in 12 of 25 genes between right- and left-sided tumours. Right-sided tumours had worse survival with a hazard ratio of 1.71 (95% confidence interval 1.10-2.64, P = 0.017). The total effect of the genetic loci on survival showed five genes had a sizeable effect on survival: DNAH5, MUC16, NEB, SMAD4, and USH2A. Lasso-penalized Cox regression selected 13 variables for the highest-performing model, which included cancer stage, positive resection margin, and mutated alleles at nine genes: MUC16, USH2A, SMAD4, SYNE1, FLG, NEB, TTN, OBSCN, and DNAH5. Post-selection inference demonstrated that mutations in MUC16 (P = 0.01) and DNAH5 (P = 0.02) were particularly predictive of 5-year overall survival.

CONCLUSIONS

Our study showed that genetic mutations may explain survival differences between tumour sites. Further studies on larger patient populations may identify other genes, which could form the foundation for more precise prognostication and treatment decisions beyond current rudimentary TNM staging.

The time Interval Between the End of Radiotherapy and Surgery Does Not Affect Outcomes in Rectal Cancer

INTRODUCTION

The ideal time interval between the completion of chemoradiotherapy and subsequent surgical resection of advanced stage rectal tumors is highly debated. Our aim is to study the effect of the time interval between the completion of chemoradiotherapy and surgical resection on postoperative and oncologic outcomes in rectal cancer.

METHODS

Patients who underwent neoadjuvant chemoradiotherapy for resected locally advanced rectal tumors between 2004 and 2015 were included in this analysis. The time interval was calculated from the date of radiation completion to date of surgery. Patients were split into 2 groups based on the time interval (<8 weeks and >8 weeks). Postoperative outcomes (anastomotic leak, pathologic complete response (pCR), and readmission) and survival were assessed with multivariable logistic regression and Cox regression models while adjusting for relevant confounders.

RESULTS

200 patients (62% male) underwent resection with a median time interval of 8 weeks from completion of radiotherapy. On multivariable logistic regression, there was no significant increase in odds between time interval to surgery and anastomotic leak (aOR = .8 [.27-2.7], P = .8), pCR (aOR = 1.2[.58-2.6] P = .6), or readmission (aOR = 1.02, 95% CI:0.49-2.24, P = .9). Time interval to surgery was not an independent prognostic factor for overall (HR = 1.04 CI = .4-2.65, P = .9) and disease-free survival (HR = 1.2 CI = .5-2.9, P = .6).

CONCLUSION

The time interval between neoadjuvant radiotherapy completion and surgical resection does not affect anastomotic leak rate, achievement of pCR, or overall and disease-free survival in patients with rectal cancer. Extended periods of time to surgical resection are relatively safe.

Zip Code-Related Income Disparities in Patients with Colorectal Cancer

INTRODUCTION

Screening and early detection reduce morbidity and mortality in colorectal cancer. Our aim is to study the effect of income disparities on the clinical characteristics of patients with colorectal cancer in Massachusetts.

METHODS

Patients were extracted from a database containing all surgically treated colorectal cancers between 2004 and 2015 at a tertiary hospital in Massachusetts. We split patients into 2 groups: "above-median income" and "below-median income" according to the median income of Massachusetts ($74,167).

RESULTS

The analysis included 817 patients. The above-median income group consisted of 528 patients (65%) and the below-median income group consisted of 289 patients (35%). The mean age of presentation was 64 ± 15 years for the above-median income group and 67 ± 15 years for the below-median income group (P = .04). Patients with below-median income were screened less often (P < .001) and presented more frequently with metastatic disease (P = .02). Patients with above-median income survived an estimated 15 months longer than those with below-median income (P < .001). The survival distribution was statistically significantly different between the groups for stage III disease (P = .004), but not stages I, II, or IV (P = 1, 1, and .2, respectively). For stage III disease, a lower proportion of below-median income patients received chemotherapy (61% vs. 79%, P = .002) and a higher proportion underwent nonelective surgery (5% vs. 2%, P = .007).

CONCLUSIONS

In Massachusetts, patients with colorectal cancer residing in lower income areas are screened less, received adjuvant chemotherapy less, and have worse outcomes, especially when analyzing those who present with stage III disease.

Infiltrating Tumor Border Configuration is a Poor Prognostic Factor in Stage II and III Colon Adenocarcinoma

INTRODUCTION

Tumor border configuration (TBC) is a prognostic factor in colorectal adenocarcinoma; however, the significance of TBC is not well-documented in colon adenocarcinoma alone.

OBJECTIVE

Our aim was to study the effect of TBC on overall and disease-free survival in stage II and III colon adenocarcinoma.

METHODS

We included patients with stage II and III colon adenocarcinoma who were surgically treated at a tertiary medical center between 2004 and 2015, to ensure long-term follow-up. Patients were stratified into four groups based on stage and TBC. A Cox regression was used to model the relationship of groups while accounting for relevant confounders.

RESULTS

The cohort consisted of 700 patients (371 stage II and 329 stage III). Infiltrating TBC was statistically significantly associated with stage (p < 0.001) and extramural vascular invasion (p < 0.001), but not histologic grade (p = 0.7). Compared with pushing TBC, infiltrating TBC increased the hazard of death by a factor of 1.8 [95% confidence interval (CI) 1.4-2.4; p < 0.001] and 1.7 (95% CI 1.3-2.2; p < 0.001). The hazard of death in patients with stage II disease (infiltrating TBC) or stage III disease (pushing TBC) was not significantly different (adjusted hazard ratio 1.1, 95% CI 0.7-1.7; p = 0.8).

CONCLUSION

Infiltrating TBC is a high-risk feature in patients with stage II and III colon adenocarcinoma. Stage II disease patients with infiltrating TBC and who are node-negative should be considered for adjuvant chemotherapy.

Octogenarians present with a less aggressive phenotype of colon adenocarcinoma

BACKGROUND

Octogenarians constitute a growing percentage of patients diagnosed with colon malignancies. This study aims to determine if the clinical and pathologic presentation of octogenarians with colon cancer differs from that of patients diagnosed at a younger age.

METHODS

Data were collected retrospectively for all patients diagnosed with colon cancer who underwent resection at a single institution between January 1, 2004 and December 31, 2017; patients with rectal cancer were excluded. Patients were categorized by age at diagnosis: either 50 to 79 years of age or ≥80 years of age; those <50 years of age were excluded because of the greater risk of a hereditary etiology. The primary outcome was the correlation between patient age and pathologic features of the tumor, including tumor size, lymph node metastases, perineural invasion, and extramural venous invasion.

RESULTS

Of 1,301 patients, 329 (25%) were ≥80. Female patients predominated the octogenarian cohort (61% vs 39%; P < .001). Octogenarians presented with larger tumors when compared to patients age 50 to 79 (5.2 cm vs 4.5 cm; P < .001). More patients ≥80 had tumors which were >8 cm (17.3% vs 8.9%; P < .001). Tumors in younger patients were more often detected on screening colonoscopy (23.1% vs 7.3%; P < .001). Regardless of tumor size, octogenarians were less likely to have positive lymph nodes than younger patients (P = .02). In addition, octogenarians were less likely to exhibit extramural venous invasion compared to younger patients across all tumor sizes (P < .001). Younger patients had greater median overall survival (6.4 years vs 4.4 years; P < .001), yet 3-year disease-free survival was comparable between age groups (P = .12).

CONCLUSION

Octogenarians with colon cancer present with larger tumors but appear to have less aggressive disease, as reflected in a lower pathologic stage, less extramural venous invasion, and less lymph node metastases, than younger patients with similar size tumors. Three-year disease-free survival is comparable between octogenarians and patients aged 50 to 79.