Assessing Steroid Toxicity in the Elderly with Multiple Myeloma

Background

The mainstay of treatment for Multiple Myeloma (MM) includes various combinations of chemotherapy, which generally includes high dose steroids. The median age at diagnosis for MM is above 60 years. Patients above the age of 70 may not be considered for an auto peripheral blood transplant, resulting in being treated with chemotherapy alone. This often leads to a relatively long period of steroid exposure. Increasing age is a risk factor for decreased tolerance to steroids, and increased drug toxicity. As such, the steroid dose (usually Dexamethasone) is often considered for reduction in patients above a certain age. However, there are no clear guidelines regarding a standard dose to use in the elderly, nor is there uniformity among clinicians in the way doses are chosen.

Purpose

To assess a) the starting dose of Dexamethasone (dex) in the elderly, b) frequency of dose reduction of dexamethasone, c) adverse effects of dex treatment in the elderly with MM, and d) average time after dose reduction.

Methods

We performed a 10 year retrospective chart review on patients, age 70 or greater treated at Henry Ford Health System with a diagnosis of MM from 2000-2015. Patients were grouped by age 70-75 years, 76-80 years, and greater than 80 years based on when treatment was initiated. We investigated the starting treatment dose of dex, ranging from 1-20 mg weekly and 21-40 mg weekly. Secondly, we assessed for the occurrence of dose reduction; and, if present, the length of time to reducing the dose. Lastly, the types of adverse effects to dex leading to dose reduction were grouped by system, such as, central nervous system, musculoskeletal, endocrine, gastrointestinal and psychiatric. Data collected was categorical, thus, no statistical tests were performed as this was a descriptive study.

Results

A total of 150 patients were reviewed and 91 patients met the inclusion criteria. Of these patients, 8 (8.8%) were started at doses between 1-20 mg and majority (62.5%) were ages 70-75, thus, there was no relation between lower starting dose and age.

Of the 91 patients, 24 (26.4%) had a dose reduction and 11 (12.1%) had both chemotherapy and dex discontinued prior to therapy completion. Majority (87.5%) of patients that had a dose reduction were initially started at 40 mg. The reasons for dose reduction included adverse effects grouped by musculoskeletal (29.17%), psychiatric (16.67%), endocrine (12.3%), central nervous system (4.17%), and gastrointestinal (4.17%). Of note, 8 patients (33.3%) had dose reductions as result of their clinical trial requirement.

The average length of dex therapy before dose reduction was 17.2 months.

Conclusion

The majority of elderly patients (age 70 or above) with MM tolerated full doses of dex without adverse effects. Secondly, there was no relation between lower starting dose for dex and advanced age. However, since there were limited patients (n=8) who started at a low dose, other than those on clinical trials, we were not able to do a comparison of starting doses. But we were able to show that the majority of patients tolerated full dose, despite their age. The most frequent cause of steroid toxicity was musculoskeletal, such as leg swelling. On average, elderly patients were able to tolerate full dose of dex for over 1 year prior to requiring a dose reduction.

Summary

Our data demonstrates no correlation between advanced age in MM and lack of tolerability of high dose steroids. In conclusion, current findings do not justify reduced doses solely based on age alone. Future studies could include investigating statistical analysis on steroid exposure and survivorship.