Frequency and Determining Factors of Empiric Chemotherapy Dose Reduction in Patients with Non-Small Cell Lung Cancer

Non-small cell lung cancer (NSCLC) is a disease of the elderly with a median age diagnosis at seventy-one years of age . Unfortunately, the risk of chemotherapy toxicities, such as mucositis, myelosuppression, neuropathy, and cardiomyopathy, increases with advancing age.

 It has been estimated that frailty in elderly cancer patients can be as high as 42%. This has led to the practice of empiric chemotherapy dose reductions (ECDR) in elderly patients to prevent morbidity and mortality. A multisite cohort study involving elderly cancer patients demonstrates that 29% of those with advanced cancer have experienced a dose reduction in their first chemotherapy cycle.

There are existing guidelines on chemotherapy dosage for patients with NSCLC. However, no guidelines are available in assisting physicians on how to manage patients with NSCLC who may also require ECDR. For that reason, clinical judgment and experience play a significant role in treatment decisions. However, this may result in potential biases and variation among physicians. Therefore, it is imperative to seek and understand the possible variables to avoid unnecessary chemotherapy toxicities in the frail elderly or under treatment of fit elderly patients. To date, there are few existing studies that explore potential factors in ECDR in the specific population such as elderly and obesity but not in NSCLC population

This study aims to determine the frequency and key factors regarding empiric chemotherapy dose adjustments in patients with NSCLC.

Methodology

We obtained ethics approval from Sunnybrook Research Ethics Board on October 2014. We conducted a retrospective study utilizing hospital chart review and Cancer Care Ontario’s Oncology Patient Information System (OPIS). We included patients from 2013-2014 with histologically confirmed NSCLC of all stages, who were receiving chemotherapy for all treatment intent in Odette Cancer Centre, Sunnybrook Health Sciences Complex. 

We defined ECDR as any decreases in the prescribed chemotherapy dosage as compared to the initial pre-calculated chemotherapy dosage by OPIS. We excluded patients with other types of lung cancers, not receiving chemotherapy, receiving oral chemotherapy, or participating in clinical trials. There was no exclusion criteria based on ages, genders, ethnicities, or otherwise. We identified the eligible patients via computerized order entry database at Odette Cancer Centre which captured all NSCLC patients during this time period. 



Results

Our study population (N=134) indicated similar demographic distribution in terms of gender (47% male vs. 53% female). Most patients resided in the GTA (76%). The patients were aged 61 and above (74%), within the normal BMI (58%), and presented with stage 4 NSCLC (78%) at the time. 

Nearly half (47%) of the patients had kidney disease of varying stages (34%, 38%, 28% for stage I, II, and III, respectively); 13% of the patients had cardiac disease. Less than one-tenth (7%) of the patients were found to have both kidney and cardiac diseases. The majority of the sample (74%) did not have a medical history of cancer. Approximately 46% of patients took more than 4 medications per day, with 15% and 11% of them taking anticoagulants and metformin/glyburide respectively. 

Lung cancer medical oncologists had higher rates of performing ECDR when using platinum-based chemotherapy; however, this finding did not reach statistical significance. Interestingly, none of the components of ESAS or its combinations were associated with ECDR. We suspected that major symptom burden was more related to contraindication of initiating chemotherapy rather than performing ECDR.

This study highlighted the importance of guidance in ECDR in the NSCLC population. This study showed that 33% of patients received ECDR. it is important to increase awareness of such dosing patterns and to further evaluate the association between ECDR and its intended outcomes in future studies.

To read more about this article,  visit  International Journal of Cancer Studies & Research published by scidoc publishers.