Outcome of rectal cancer in patients aged 30 years or less in the Pakistani population

BACKGROUND

The incidence of rectal cancer is increasing in younger age groups. Limited data is available regarding survival outcome in younger patients with conflicting results from western world. The goal of this study was to determine survival in patients with rectal cancer<30 years of age and compare it with their older counterparts in the Pakistani population.

MATERIALS AND METHODS

A retrospective chart review of patients operated for rectal adenocarcinoma between January 2005 and December 2010 was performed. Patients were divided into two groups, Group 1 aged ≤30 years and Group 2 aged >30 years. Patient characteristics, surgical procedure, histopathological details and number of loco-regional and distant failures were compared. Expected 5 year survival was calculated using Kaplan Meier curves and significance was determined using the Log rank test.

RESULTS

There were 38 patients in group 1 and 144 in group 2. A significantly high number of younger patients presented with poorly differentiated histology (44.7% vs 9.7%) (p=0.0001) and advanced pathological stage (63.1% vs 38.1%) (p=0.04). Predicted overall 5 year survival was 38% versus 57% in groups I and II, respectively (p=0.05). Disease free survival was 37% versus 52% and was significantly different (p=0.007).

CONCLUSIONS

Early onset rectal cancer is associated with poor pathological features and a worse outcome in Pakistani population.

Secondary malignant melanoma in primary mediastinal germ cell tumour

Secondary transformation in Germ Cell Tumours (GCT) is an extremely rare event. We report here a case of malignant melanoma arising in primary mediastinal GCT. A young male presented with new onset dyspnoea and a mediastinal mass. As serum alpha fetoprotein was raised, a diagnosis of primary mediastinal GCT was made. He achieved remission with standard chemotherapy and resection of the mass. After a year, he relapsed with widespread disease which on work-up revealed malignant melanoma. As examination for cutaneous melanoma was unremarkable, a diagnosis of mediastinal GCT with secondary transformation to melanoma was made. Exact origin of melanoma in GCTs is unknown, but these may occur from transformation of dermal elements or de-differentiation of germ cells to melanomas. Before making such a diagnosis, search for primary cutaneous melanoma is mandatory. No clear guidelines exist in literature for the treatment of secondary melanomas, so current management guidelines for cutaneous melanoma may be followed.

Impact of lymph node ratio and number on survival in patients with rectal adenocarcinoma after preoperative chemo radiation

BACKGROUND

Retrieval of <12 lymph nodes after proctectomy and preoperative chemoradiation (C-XRT) may improve survival in good risk patients. The objective of this study was to determine impact of <12 retrieved lymph nodes and lymph node ratio (LNR) on survival in a population with certain poor prognostic features for rectal cancer.

METHODS

Patients who underwent surgery for rectal adenocarcinoma between 2005 and 2011 were divided them into <12 or >12 lymph node groups. The LNR groups were based on interquartile range. Clinicopathological and treatment outcomes were compared. Expected 5 year disease free and overall survival was calculated. Cox proportional hazard model was used to determine independent predictors.

RESULTS

More patients in <12 lymph nodes removed group had low tumors (<5 cm from anal verge) (75.5% versus 60.7%) (P=0.03) and underwent abdominoperineal resection (59.1% versus 42.9%) (P=0.02). Overall survival (OS) and disease free survival (DFS) was not different [(56% and 52% (P=0.7)] [(50% and 57% (P=0.5)]. LNR<0.15 was independent predictor of DFS while LNR ratio<0.12 for OS on multivariate analysis.

CONCLUSION

LNR and not number of retrieved nodes impacts survival in younger patients with predominance of anorectal tumors after C-XRT. A specific LNR cutoff remains to be defined.

Impact of acellular mucin pools on survival in patients with complete pathological response to neoadjuvant treatment in rectal cancer

BACKGROUND

Rarely, patients with pathological complete response (PCR) after neoadjuvant chemoradiotherapy demonstrate acellular mucin pools. The prognostic significance of this finding is controversial. The objective of this study was to determine impact of acellular mucin pools on disease free and overall survival in patients with complete pathological response to neoadjuvant chemoradiotherapy in rectal cancer.

METHODS

One hundred and seventy two patients received neoadjuvant chemoradiotherapy for rectal cancer and underwent surgery. Patients were divided into two groups based on presence of acellular mucin pools. Locoregional failures, distant failures and deaths were compared. Expected 5 year disease free and overall survival was calculated.

RESULTS

Median follow-up was 36(4-94) months. Complete pathological response was identified in 35(20.3%) patients. Of these, 12(34.2%) had acellular mucin pools in resected specimen. Majority of mucin negative tumors were moderately differentiated (78% vs 25%) (P = 0.005). Median overall survival for mucin positive and mucin negative tumors was 4(1.3-5.7) and 3.3(0.1-6.3) years respectively. Expected 5 year disease free and overall survival for mucin positive and mucin negative tumors was 73% and 89% (P = 0.1) and 75% and 87% (P = 0.4).

CONCLUSION

Acellular mucin pools in rectal cancer following a PCR to neoadjuvant treatment do not impact survival.