The incidence of breast cancer in adolescent and young adult women (AYA) has increased since 2004, with as many as 12,000 new diagnoses per year in recent years, noted Rebecca Johnson, MD, a pediatric oncologist at Mary Bridge Children’s Hospital in Tacoma, Washington. . , and colleagues, write in a clinical review in JCO Oncology Practice.
Modifiable risk factors, therapy choice, therapeutic outcomes, and quality of life issues all differ between AYAs and older women with breast cancer, the authors explained. “AYAs face unique, age-specific challenges when faced with breast cancer treatment and survival. As a result, they benefit significantly from a coordinated, multidisciplinary treatment approach.”
In the following interview, Johnson discusses some of the challenges and special issues that younger patients with breast cancer face.
The incidence of breast cancer in adolescent and young adult women has increased since 2004, especially invasive cancer. What are the possible reasons for and implications of this trend?
johnson: The increase in breast cancer in AYA women is largely due to an increasing incidence of breast cancer with distant metastatic spread at the time of initial diagnosis. This trend started in the 1980s and has accelerated too quickly to be due to genetic changes in the population.
The reasons are not yet known. Possible explanations include changes in modifiable lifestyle risk factors or toxic environmental exposures in AYAs, compared to previous generations of women.
Further research is urgently needed. Note that obesity is a risk factor for advanced breast cancer in both young and older women.
You mentioned that AYA women with breast cancer are 39% more likely to die than their older counterparts. Why is survival worse in these patients?
johnson: First, young women are more likely than older women to be diagnosed with regional or distant spread of breast cancer (stages II-IV). A higher stage at diagnosis, especially stage IV disease, is associated with a poor prognosis.
Second, compared to older women, AYAs are more likely to be diagnosed with aggressive breast cancer subtypes, including the basal-like and HER2-enriched subtypes. The underlying reason for the over-representation of aggressive subtypes among AYAs is unknown.
AYAs have the worst cancer-specific survival of all age groups of women with breast cancer under 75 years of age. Racial differences in survival are also prominent in the AYA age group. AYA black women under the age of 35 have particularly inferior outcomes, with three times higher death rates than whites of the same age with breast cancer.
What are the modifiable risk factors that differ between AYAs and older women?
johnson: Smoking, heavy alcohol use and high red meat consumption are known risk factors for breast cancer in both AYAs and older women. There are fewer studies of modifiable risk factors unique to AYAs. Significant weight gain after age 18 has been cited as a risk factor for AYA breast cancer, as well as the triad of obesity, high calorie intake, and sedentary lifestyle. The use of oral contraceptives (especially in BRCA carriers) increases the risk of AYA breast cancer. Multiparity is a risk factor for AYA breast cancer; The incidence of breast cancer increases for several months during the postpartum period.
Breastfeeding protects against breast cancer in both young and older women. Small studies suggest that vigorous exercise during the teens and young adult years, a high vitamin D intake, and a plant-based diet may each be protective against AYA breast cancer. One study found that replacing legumes with one serving of meat per day reduced the risk of early breast cancer by 19%.
AYAs are more likely to opt for bilateral mastectomy than older women, although survival is comparable to breast-conserving therapies. Why is this and how should oncologists advise AYAs on this choice of therapy?
johnson: Young women may choose bilateral mastectomy to reduce their risk of developing a second cancer. Breast cancer AYAs have a significant lifetime incidence of second breast cancers. Survival in women diagnosed with a second, contralateral breast cancer is worse than in women with primary breast cancer.
AYAs with breast cancer are more likely than their older counterparts to have a germline cancer mutation, and NCCN [National Comprehensive Cancer Network] guidelines suggest that patients consider risk-reducing bilateral mastectomy in this setting.
Body image concerns and functional concerns can also influence surgical decisions. Breast symmetry may be better preserved after bilateral mastectomy with reconstruction compared to lumpectomy or unilateral mastectomy, prompting some young women to choose bilateral mastectomy. Breastfeeding is not possible after bilateral mastectomy, but is possible after unilateral mastectomy, especially if radiation therapy is not necessary.
AYAs with breast cancer more often report a reduced quality of life than older patients. Why is this and does it affect their adherence to treatment?
johnson: Compared to female survivors of other cancers of the same age, young women with breast cancer report impaired cognitive functioning and greater fatigue. Young breast cancer survivors may have ongoing problems with anxiety, depression, and anxiety. It is unknown whether psychosocial factors have a direct influence on adherence in this population. Studies in the general population of cancer patients suggest that lower levels of depression and anxiety may positively affect adherence.
Sexual side effects and the desire to have children can affect AYAs’ willingness to comply with recommended hormonal therapy and ovarian suppression. AYAs treated with tamoxifen, with or without suppression of ovarian function, are at risk for vaginal dryness, hot flashes, and sexual dysfunction. These symptoms can be so severe that some AYAs with early-stage disease choose not to take these drugs. Some AYA breast cancer survivors also choose to forego, interrupt, or stop taking tamoxifen to conceive.
Read the clinical review here and expert commentary on the clinical implications here.
Jeff Minerd is a freelance medical and scientific writer based in Rochester, NY.
Johnson reported relationships with Servier and Jazz Pharmaceuticals.