Abstract 1843P
Background
Cancer incidence, comorbidity, and polypharmacy increase with advanced age. The impact of the interplay between these factors on receipt of systemic therapy (ST) in advanced malignancy has rarely been studied and is the focus of this study.
Methods
A retrospective cohort study was conducted including patients ≥18 years diagnosed with multiple myeloma (MM) (all stages), non-Hodgkin’s lymphoma (NHL) (stage III-IV), breast (stage III-IV), lung (stage IV), colorectal (CRC) (stage III-IV), prostate (stage III-IV) or ovarian cancer (stage IV) from 2004 to 2015 in Manitoba, Canada. Cancer stages were only included if standard care included ST. Clinical and administrative health data were used to determine demographic and cancer characteristics, treatment history, comorbidity (Charlson Comorbidity Index (CCI) and Resource Utilization Band (RUB)) and polypharmacy (≥6 medications). Multivariable logistic regression was used to evaluate the association of variables with receipt of ST and interactions with age.
Results
17,228 patients were diagnosed with advanced cancer over the 12-year timeframe. Individuals diagnosed by cancer type was 29% for CRC, 28% for lung cancer, 13% for prostate cancer, 12% for breast cancer, 10% for NHL, 5% for MM and 4% for ovarian cancer. 24% of patients were <60 years, 26% between 60-69, 26% between 70-79, 19% between 80-89 and 5% were ≥90 years. ST therapy was administered to 50% of patients. Increasing age, higher RUB and CCI, unknown stage cancer, and higher medication count each decreased the odds of ST (each p<0.01). Significant interaction effects were found between age at diagnosis with stage of cancer and cancer type (each p<0.001). There was substantial variation in the likelihood of ST receipt depending on the underlying malignancy, with MM being the most likely and lung cancer the least. Stage IV had a lower probability of ST than stage III at younger ages, with similar rates at increased ages.
Conclusions
Our large, population-based analysis found that for advanced cancers increased age, polypharmacy, and comorbidity each independently decreased the likelihood of receiving ST. There was substantial variation of receipt of ST based on the underlying malignancy. Age interacted with stage and cancer type.
Clinical trial identification
Editorial acknowledgement
Legal entity responsible for the study
The authors.
Funding
Canadian Institutes of Health Research.
Disclosure
All authors have declared no conflicts of interest.