Androgen Deprivation Therapy (ADT) or Hormone Therapy (HT) to treat prostate cancer is a mainstay of therapy for men with recurrent or metastatic disease. There are many side effects associated with ADT including weight gain.   Weight gain, an adverse metabolic change, may contribute to cardiovascular comorbidity.  A better understanding of the risk factors for weight gain on ADT is important for optimal management of ADT associated side effects.

A retrospective review assessed weight change among 118 men with non-metastatic prostate cancer treated with ADT. The primary endpoint was weight change at one year from the start of ADT with the secondary aim to stratify the risk of weight gain by baseline patient characteristics.

Men in the study exhibited a significant increase in weight (p=0.0005) during the first year following ADT initiation. The researchers identified three risk factors for weight gain for men on ADT treating prostate cancer:

1-   Men younger than age 65 (5.98 pounds gained, p=0.001 vs. 1.63 pounds, p= 0.09 for age 65+)

2-    Men with a body mass index (BMI) less than 30 (4.36 pounds gained, p=0.00002 vs. 0.22 pounds, p=0.87 for BMI 30+)

3-    Men who were not diabetic (3.43 pounds gained, p=0.0003 vs. 0.57 pounds, p=0.74 for diabetics).

They found that men who were younger than age 65, had a BMI less than 30, and where not diabetic were each significantly associated with weight gain one year after starting ADT. Increasing weight gain was strongly associated with increasing number of baseline risk factors. Although metabolic consequences were previously considered most significant for men with preexisting comorbidity, these data suggest younger, slimmer, and non-diabetic men may be at higher risk for gaining weight on ADT.

The researchers believe that these three categories of men generally have higher endogenous testosterone (T) levels prior to starting ADT when compared to older, obese, and diabetic men.  The magnitude of T decline following the start of ADT might explain the bigger weight gain.

J Clin Oncol 32, 2014 (suppl 4; abstr 80): Daniel Martin Seible, Xiangmei Gu, Andrew Hyatt, Clair Beard, Jason Alexander Efstathiou, David Tomoaki Miyamoto, Timur Mitin, Neil E. Martin, Joshua Beckman, Shehzad Basaria, Paul Linh Nguyen

JoelT. Nowak, M.A., M.S.W.