The impact of low-grade toxicity in older people with cancer undergoing chemotherapy

Background: Significant toxicity in chemotherapy trials is usually defined as grade >= 3. In clinical practice, however, multiple lower grade toxicities are often considered meaningful. The purpose of this observational cohort study was to identify which level of toxicity triggers treatment modification and early discontinuation of chemotherapy in older people. Methods: Patients aged 65+ were recruited in a central London hospital. A total of 108 patients were recruited at the start of new chemotherapy treatment between October 2010 and July 2012. Results: Mean age was 72.1 +/- 5 years, median 72 and range 65-86 years. Of the patients, 50.9% (55) were male with gastrointestinal (49), gynaecological (18), lung (15) and other cancers (26). Chemotherapy was palliative in 59.3% (64/108), curative/neoadjuvant/adjuvant in the others. Mean number of cycles completed was 4.2 +/- 3. Treatment modifications due to toxicity occurred in 60 (55.6%) patients, 35% (21/60) of whom had no greater than grade 2 toxicity. Early treatment discontinuation because of toxicity occurred in 23 patients (21.3%), 39.1% (9/23) of whom had no greater than grade 2 toxicity. Conclusions: Many older patients did not complete treatment as planned. Treatment was modified/discontinued even for one or two low-grade toxicities. Further work is required to clarify whether low-grade toxicity has a greater clinical impact in older people, or whether clinicians have a lower threshold for modifying/discontinuing treatment in older people.