Cancer researchers know that age bears on how a patient's cancer will progress, what types of treatment might be most effective for that patient, and the decisions that patient might make about his or her treatment.
But now, new data published earlier this year in the American Society of Breast Surgeons 2020 Virtual Scientific Session Official Proceedings sheds more light on tumor characteristic and treatment decision differences for women younger than 40 with HER2-positive breast cancer and women older than 40 (Abstract 787537). The Official Proceedings is an online compilation of peer-reviewed research selected for presentation at the 2020 Annual Meeting of the American Society of Breast Surgeons, which was cancelled because of the COVID-19 pandemic.
For the study, the researchers analyzed data from the National Cancer Database that included 26,262 women younger than 40 and 28,537 women 40 or older with breast cancer. The data showed the following:
* Younger patients presented with a higher clinical stage cancer compared to older patients with 37.16 versus 61.78 percent at stage I, 45.92 versus 29.50 percent at stage II, 12.79 versus 6.17 percent at stage III, and 4.13 versus 2.55 percent at stage IV. Pathologic stages for these women were also significantly higher.
* A total of 44.48 percent of women under 40 and 68.95 percent of the older patients had grade I and II tumors, while 55.52 percent of those under age 40 and 31.06 percent of older patients had grade III and IV tumors-meaning that significantly more young women had poorly differentiated cancer cells correlating with more aggressive disease.
* A total of 22.63 percent of younger women were HER2-positive compared with 13.41 percent of older women.
* A total of 19.82 percent of younger women had difficult-to-treat triple-negative breast cancer, compared with approximately half that number in older patients.
* In a comparison of therapeutic intervention, patients under 40 were more likely to have been treated with chemotherapy, while radiation therapy was more common among those ages 40 and over.
Here's what else study co-author Kelly Krupa, MD, a resident researcher at Allegheny General Hospital, told Oncology Times about the research.
1 What were the key findings from this research and how are they different from what we previously knew?
"In general, women younger than age 40 present with invasive breast cancer with more aggressive features; therapies are still developing to treat these patients and improve outcomes. It is also important to acknowledge that these patients face unique challenges that influence treatment. For example, fertility preservation and survivorship are important in the younger patient population.
"Prior to this study there was limited data on HER2 status in the young patient population with invasive breast cancer. [This data show] women under age 40 were more likely to present with a higher grade tumor, be ER-negative, and be HER2-positive. Across staging systems, women under the age of 40 had greater odds of presenting at a later stage. Patients under age 40 were also more likely to receive chemotherapy."
2 Now that this data is available, how can it be put to use to improve treatments for patients? What's the next step of your work?
"This data is consistent with other reports that patients under the age of 40 presenting at a later stage with more aggressive features, including hormone receptor-negative, HER2-positivity, and with a higher grade compared to patients over the age of 40. These unique features suggest this patient population should be treated as its own entity.
"More research needs to be conducted to better understand the presentation, tumor biology, and treatment effectiveness of specific therapies. This will allow targeted treatment for these patients. Patients under the age of 40 with invasive breast cancer are being treated with the current standard of care.
"Currently, the National Cancer Database does not have information about genetics and risk factors, such as family history. Those factors would be interesting to study. It is important to educate medical professionals about the unique features of young breast cancer patients so they can be appropriately treated and risk-stratified."
3 So, what's the bottom-line message practicing oncologists and cancer care providers should know about this work?
"The younger-than 40-year-old age group [of patients] with breast cancer is its own unique entity and should be treated as such.
"Physicians should have different discussions regarding breast cancer treatment in young women. Particular issues of concern include fertility, career sustainability, child care, sexual function, breast cancer during pregnancy, body image, psychosocial distress, premature menopause, and potential long-term complications from therapy. Prognosis and survivorship including metastases are also important. These patients should be offered genetic counseling, referrals to fertility clinics, and mental health services."