The use of adjuvant (postoperative) therapy in patients with DCIS (whether or not related to PDB) is still debated. For patients with invasive cancers, both radiation therapy and chemotherapy are usually indicated. The decision to use neoadjuvant (preoperative) chemotherapy is made on a case-by-case basis. All decisions are based on the nature of the underlying cancer, regardless of whether the diagnosis is PDB.
Because PDB is categorized as invasive in at least 85% of cases, and because all invasive breast cancers carry about twice the risk for newly diagnosed contralateral disease, systematic follow-up is extremely important for patients with PDB. A clinical exam and updated history should be performed every four to six months during the first two years and at least annually after that. Screening recommendations, including a yearly mammogram, remain the same for asymptomatic patients. Patients with new or recurring symptoms—because they are at high risk for cancer recurrence—or who are undergoing treatment may have additional testing, including assessing for tumor markers, ultrasound, or MRI.2
PDB is treated with the same chemotherapy regimens as other breast cancers. In the early stages, chemotherapy reduces the risk for recurrence. In advanced breast cancer, the goal of chemotherapy is to reduce tumor size and achieve local control.
Prognosis
Patients with negative lymph node biopsy results have survival rates of 85% and 79% at five and 10 years, respectively. Patients with positive node results face survival rates of 32% at five years and 28% at 10 years. As with other cancers, anything that contributes to disease progression (including delayed diagnosis or treatment) decreases the patient’s survival rate.2,3 The overall prognosis for PDB is based on the nature of the underlying breast cancer, including its stage and other predictive factors—not on the fact that it is PDB.
Patient Outcome
Nearing the end of her treatment with trastuzumab, the patient became concerned about new-onset vaginal and left pelvic pain, along with some lower back discomfort. She mentioned these symptoms to her oncologist immediately. A transvaginal ultrasound could not rule out an ovarian neoplasm.
The patient elected to undergo total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH/BSO). This option allowed for removal of a mass discovered during the procedure, minimized the risk for subsequent endometrial cancer, and reduced the chance of recurrence of the patient’s estrogen/progesterone receptor–positive breast cancer. The mass itself turned out to be a benign pedunculated fibroid tumor.
The patient was relieved and continues to recover well. A follow-up PET/CT scan is scheduled for three months from now.
Conclusion
PDB is a complex disease that challenges our current understanding of breast cancer and its diagnosis and treatment. It depends uniquely upon ductal (versus blood or lymphatic) spread. Little did Paget and his contemporaries realize they had opened up such a porthole into modern histology. Nor did they appreciate the fact that they had identified an insidious breast cancer that declares itself through the skin.
Today, it is understood that by the time nipple changes of PDB appear, an underlying breast cancer most likely exists. In at least 25% of cases, there is neither a palpable mass nor a positive mammogram finding. For this reason, clinicians must maintain a high level of clinical suspicion and a low threshold for biopsy when there are skin changes at the nipple. This is especially true because the underlying lesions are more likely to be invasive cancers.
Surgical treatment will often mean complete mastectomy, whether simple, modified radical, or radical. This choice will be driven by the extent and location of the underlying disease. There is a role for partial mastectomy followed by radiation therapy in those rare cases in which PDB is confined to the NAC with no underlying tumor. Partial mastectomy is also a consideration when the underlying tumor is small and/or located close to the NAC. Patients with PDB may consider whole-breast or NAC reconstruction once radiation therapy and/or chemotherapy are completed.
PDB remains a poignant reminder for all clinicians of the importance of a thorough clinical exam and a well-focused history in all patients at risk for breast cancer. Moreover, it is an enduring example of the fact that common symptoms sometimes do signify something uncommon and potentially life- changing.
References
1. Paget J. On disease of the mammary areola preceding cancer of the mammary gland. In: Paget S, ed. Selected Essays and Addresses by Sir James Paget. London: Longmans, Green and Co.; 1902:145-148.
2. Sabel MS, Weaver DL. Paget disease of the breast. In: UpToDate. Chagpar AE, Hayes DF, Pierce LJ, eds. www.uptodate.com/contents/paget-disease-of-the-breast. Updated November 27, 2012. Accessed September 9, 2013.