NEW YORK (Reuters Health) – A substantial proportion of women with cervical cancer who receive curative-intent radiotherapy will soon develop pelvic fractures, clinicians from the University of Texas M. D. Anderson Cancer Center in Houston have found.
Therefore, “bone mineral density screening and pharmacologic intervention should be considered in these women,” lead author Dr. Kathleen M. Schmeler commented in an email to Reuters Health.
As Dr. Schmeler and her colleagues note in the January 5th online issue of Cancer, earlier studies showed that radiation to the pelvis “results in demineralization of bone matrix, with a pelvic fracture rate of 2% to 89%” in women with gynecologic malignancies.
Because of certain limitations in these studies, Dr. Schmeler’s group examined the incidence of pelvic fractures and associated risk factors in 300 women who underwent curative-intent radiotherapy for cervical cancer between 2001 and 2006. The median follow-up for all patients was 20.9 months, and the median interval from the end of treatment to the last imaging study (either CT or MRI) was 7.4 months.
None of the women had bony metastases or a pelvic fracture history at baseline. During follow-up, 29 women (9.7%) developed pelvic fractures; 23 had received primary radiotherapy and 27 had also been treated with cisplatin or cisplatin plus 5-fluorouracil.
“Given that our median age was 47.4 years and 40% of our patients were premenopausal at the start of treatment, it is estimated that an age-matched population of women not receiving radiation therapy would have a background fracture rate of less than 5%,” Dr. Schmeler noted.
Only 13 women had fracture symptoms, most commonly pain. Fracture sites included the sacrum (83%), sacrum and pubis (10%), iliac crest (3.5%), and sacrum and acetabulum (3.5%).
Older age at cancer diagnosis, postmenopausal status and lower body mass index were associated with higher fracture risks.
It’s important to note, Dr. Schmeler said, that the median interval from the end of radiation therapy to the fracture diagnosis was only 14 months, with 38% of fractures diagnosed within 1 year and 83% of fractures diagnosed within 2 years after treatment.
“Because radiation therapy cures many of these patients, the long-lasting effects such as osteoporosis and pelvic fractures need further attention,” Dr. Schmeler concludes.
To better assess the effects of radiation on bone, she and her colleagues are currently measuring changes in bone mineral density and serum markers of bone turnover in women undergoing pelvic radiation therapy for gynecologic cancers.