Prevalence of comorbidity in cancer patients scheduled for systemic anticancer treatment in Austria

The purpose of this observational study was to determine the prevalence of comorbid conditions in cancer patients with solid tumours selected for specific treatment at 12 divisions of medical oncology in Austria. Data from 1137 patients were collected using a standardized questionnaire; of these, 1036 datasets were evaluable for further analysis. Data were prospectively collected from patients during an in- or outpatient hospital visit over a 4-month period in 2011. Of these patients 42% had gastrointestinal cancer, 31% had breast cancer, 9% lung cancer and the remaining had urogenital cancer, sarcoma or other types of rare cancers. Around two-thirds of patients had metastatic disease (59%), confined to a single organ site in 55% of patients. A high proportion of patients had a good performance status (Eastern Cooperative Oncology Group [ECOG] 0, 1: 82%). Comorbid conditions were classified according to the Charlson scheme score and were present in 86% of patients with a median age of 64 years. The predominant conditions were cardiovascular diseases (57%), metabolic diseases (44%), endocrinological diseases (30%), gastrointestinal diseases (26%), neurological (23%) and respiratory diseases (23%). As has been reported by others we found a clear association between number of comorbid conditions and age. While 60% of the whole population had at least 2 comorbidities, most patients of the elderly population (89%) had more than three comorbidities. The high proportion of patients with comorbidities and accompanying medication represents a substantial challenge for medical oncologists in selecting the optimal cancer-specific treatment especially in the era of novel targeted and immunotherapies. Comorbid conditions and accompanying comedications require special precautions concerning potential interactions and unexpected adverse reactions from prescribed tumour-specific treatment.