Developing a Stacked Ensemble-Based Classification Scheme to Predict Second Primary Cancers in Head and Neck Cancer Survivors

Despite a considerable expansion in the present therapeutic repertoire for other malignancy managements, mortality from head and neck cancer (HNC) has not significantly improved in recent decades. Moreover, the second primary cancer (SPC) diagnoses increased in patients with HNC, but studies providing evidence to support SPCs prediction in HNC are lacking. Several base classifiers are integrated forming an ensemble meta-classifier using a stacked ensemble method to predict SPCs and find out relevant risk features in patients with HNC. The balanced accuracy and area under the curve (AUC) are over 0.761 and 0.847, with an approximately 2% and 3% increase, respectively, compared to the best individual base classifier. Our study found the top six ensemble risk features, such as body mass index, primary site of HNC, clinical nodal (N) status, primary site surgical margins, sex, and pathologic nodal (N) status. This will help clinicians screen HNC survivors before SPCs occur.

Types of second primary cancer influence overall survival in cutaneous melanoma

Background Favorable survival in malignant cutaneous melanoma (melanoma) has increased the likelihood of second primary cancer (SPC). We assess the influence of patient characteristics at diagnosis of first melanoma and the type of SPC (second melanoma and other SPC) on overall survival. Methods We used the Swedish Cancer Registry data to assess overall survival in melanoma for the period 1990 to 2015. Kaplan-Meier curves were plotted and hazard ratios (HRs) were estimated with Cox regression models by considering SPC diagnosis as a time-dependent variable. Results A total of 46,726 patients were diagnosed with melanoma, and 15.3% of them developed SPC, among which, two thirds were other SPCs. Second melanomas were diagnosed early (31% during the first year) compared to non-melanoma SPCs (9.5%). Survival for women with second melanoma or other SPC (56 and 21% alive after 25 years of follow-up, respectively) exceeded the male rates (21 and 10%, respectively) but all these figures were lower than for females (60% alive) or males (48%) without SPC. Time dependent analysis showed vastly increased HRs for cancer types that are fatal also as first cancers, but SPC-specific HRs remained relatively uniform, irrespective of SPC diagnosed soon or late after first melanoma. In early-onset melanoma, SPC diagnosis after 10 years may not negatively influence overall survival. Conclusions As the overall survival of patients with many types of SPCs is unfavorable, advice about health lifestyle should benefit smoking patients and early detection methods may be recommended for SPCs of the breast, prostate and colorectum.

239Incidence and potential risk factors of a second primary cancer among 217,702 colorectal cancer survivors

Background Survival of colorectal cancer (CRC) has improved markedly but risk of an independent second primary cancer (SPC) increases. We determined incidence and potential risk factors of SPC following CRC. Methods We obtained data from 217,202 CRC cases (ICD-10 C18-C20, aged ≥20 years) diagnosed between 1990-2013 from the German Centre for Cancer Registry Data. Cancers arising in a distinct site (excluding non-melanoma skin cancer) and/or of a different histology group were classified as SPCs. Standardised incidence ratios (SIR) and 95% confidence intervals compared the excess risk to the general population, stratified by age, sex and CRC sub-site. Cox proportional hazards models identified potential risk factors of SPC. Results Following CRC (median age 70 years), 18,751 SPCs occurred (8.63%; median age 69 years). SPC incidence increased by 36% in males (SIR: 1.36 [1.34-1.38]), 46% in females (SIR: 1.46 [1.43-1.49]) and doubled for cases <65 years (SIR: 2.08 [1.99-2.17]). Common SPC sites following colon cancer included the small intestine, stomach, liver, pancreas, bladder and kidney. Common male-specific sites included prostate and in females: breast, uterus and ovary. Similar sites were observed following rectal cancer, particularly in cases <65 years. Age, male sex and tumour size (T1, T2) were potential risk factors of SPC. Therapy of CRC (including radiotherapy) did not demonstrate an elevated risk. Conclusions CRC survivors have an increased risk of SPC, particularly due to age, sex and tumour size. Key messages Colorectal cancer survivors have an increased risk of a SPC. Age, sex and tumour size are associated risk factors.