Late Effects of Radiotherapy in Gynecologic Cancers

Mary McCormack, BSc, MSc, PhD, MBBS

Ahead of the 2016 American Society of Clinical Oncology (ASCO) Annual Meeting, held June 3–7 in Chicago, we are today discussing ways to improve the care of patients with gynecologic cancers with Mary McCormack, BSc, MSc, PhD, MBBS, FRCR, of the University College Hospital in London. At this year’s meeting Dr. McCormack will present, “Surviving the Cure: Managing Late Effects of Radiotherapy,” at an education session on symptom management in patients with gynecologic cancers.

- Interviewed by Anna Azvolinsky 

Cancer Network: So, first, what are typically the immediate effects of radiotherapy in women with gynecologic cancers?

Dr. McCormack: The immediate effects are generally related to the bowel and the bladder. It is quite common for the bowel habits to change during radiotherapy, and we tend to see an increased frequency of bowel movements and sometimes rectal bleeding or straining, pain is not uncommon. Patients may need to make alterations to their diet and may need to take certain medications to bulk up the stool. With respect to bladder function, dysuria and frequency are very common, and patients are generally advised to drink plenty of fluids to avoid dehydration and to avoid acidic juices, which can sometimes exacerbate the symptoms.

I think it’s very important that we explain to these women that these symptoms are generally temporary and that most will improve once the course of radiotherapy is completed.

Cancer Network: When do most late effects of radiotherapy occur and what are some of those?

Dr. McCormack: Late effects are defined as those that occur after a latent period of months to years. And usually, it's a minimum of 3 months after completion of treatment that we would consider an affect to be a late effect of radiotherapy. Again, the late effects of radiotherapy are going to be related to the tissues that were within the radiation field-for gynecologic and pelvic malignancies this will be the bladder and bowel. There can also be late effects on the bones, and it is not unusual to see pelvic insufficiency fractures in these women at follow-up. Lymphedema is also another concern, particularly in patients who have had lymph node dissections. Of course, sexual function can be impaired and can really be a major issue for a lot of women after pelvic radiotherapy.

Cancer Network: Are there certain patients that are more likely to experience these later effects?

Dr. McCormack: Generally speaking, we tend to find that patients with a low body mass index tend to experience more toxicity. Also, patients who smoke tend to have worse toxicity, but the mechanisms for this are not entirely understood. I think we also tend to see more side effects in patients who have had treatment for cervical cancer, possibly because those patients are treated to a higher radiation dose than women who receive radiotherapy for, say, endometrial cancer, where the radiation dose is lower and given in the adjuvant setting rather than as radical treatment.

Cancer Network: What can clinicians do to better follow-up with these cancer survivors to mitigate some of these late effects?

Dr. McCormack: I think probably the key aspect here is to recognize that there are a number of late effects of radiotherapy and that we will all tend to think about and look out for the very serious side effects such as bowel fistulas or excessive hematuria or rectal bleeding. It’s important to recognize that it’s often the little things that get patients down-that is, if they have a lot of grade 1/2 symptoms.

These can actually be quite troublesome for the patient and maybe perhaps they are less well-recognized by physicians, because we tend to assume that if they are just grade 1/2 symptoms that they are not particularly troublesome-but these can have a huge impact on patients’ quality of life. It is important to recognize that these symptoms can have an impact on patients’ well-being and functions, and to warn patients and counsel them appropriately in advance of treatment on what to look out for, and to give them pointers on what they can do and inform them that if they develop these symptoms during their follow-up that they should bring it to the attention of their oncologist.

Ideally, their oncologist will have a pathway for referring those patients to the appropriate specialist, particularly the urologist or gastroenterologist who understand the effects and impact of radiotherapy on the bladder and the bowel.

Cancer Network: Thank you so much, Dr. McCormack, for joining us today.

Dr. McCormack: Thank you.