Re: 18F-Fluorocholine PET/CT of Incidental Male Breast Cancer
We read with interest the article of Hugentobler et al1 describing the case of a man with prostate cancer history presenting intense uptake in his right breast and moderate uptake in right axillary lymph node at 18F-fluorocholine PET/CT (confirmed also at a complementary 18F-FDG PET/CT), being invasive ductal cancer with axillary node invasion at postsurgical histological analysis.
Recently, we dealt with a similar condition. The patient is a 77-year-old patient who underwent 12 years earlier total prostatectomy because of a prostate adenocarcinoma (Gleason 3 + 4), followed by hormonal therapy. Biochemical follow-up disclosed increase in serum prostate-specific antigen (PSA) levels (up to 4.13 μg/L at last control), suggestive of recurrence of disease. 18F-fluorocholine PET/CT scan, performed to detect the site of relapse, demonstrated the presence of an area of mild tracer accumulation in correspondence of a left lumbar para-aortic lymph node; in addition, this scan revealed a focal area of radiopharmaceutical uptake in a breast retroareolar node and an area of slight tracer accumulation in a left axillary lymph node (Figs. 1A–C). Ultrasound evaluation showed a 14-mm hypoechoic nodule (Fig. 1D) in the context of left gynecomastia and a morphologically altered omolateral axillary lymph node, suggestive of malignancy. The suspicion was confirmed by fine-needle aspiration cytology performed on the left breast nodule. The patient underwent surgery. Histological analysis demonstrated the presence of an infiltrating carcinoma of the left male breast with tubular features and desmoplastic reaction (Ki-67 = 8%) coexisting with intraductal carcinoma with cribriform and micropapillary features; immunohistochemical positivities for CK19, estrogen receptor, progesterone receptor, E-cadherin 56, p53, and PSA (Fig. 1E) were found; the axillary lymph node was proved to be metastatic. A subsequent determination for PSA showed no decrease in its serum levels (5.53 ng/mL).
Breast cancer is approximately 100 times less frequent among men with respect to women; on the other hand, choline PET imaging may be useful for breast cancer, and it may be a valuable option for patients harboring fibrocystic breast changes impairing mammography and FDG PET/CT performance.1
Recently, another case by Vadrucci et al2 reported a 79-year-old man undergoing 18F-fluorocholine PET/CT because of biochemical recurrence of prostate cancer: images showed an area of elevated radiopharmaceutical uptake in a left pelvic node and a small focus of increased radiolabeled choline accumulation in correspondence of a right breast small nodule, which at histology was found to be an infiltrating ductal carcinoma. Moreover, Kwee and Coel3 reported a prostate cancer patient undergoing 18F-fluorocholine PET/CT for disease staging, which revealed an incidental synchronous breast cancer.
Increased testosterone and 17β-estradiol levels are commonly observed during antiandrogen monotherapy, leading to gynecomastia and breast pain.4 In this context, estrogen receptors' presence may increase breast cancer risk in men undergoing hormonal therapy. Recently, the combined effects of established breast and prostate cancer susceptibility variants on cancer risks for male carriers of BRCA1/2 mutations by constructing weighted polygenic risk scores have been investigated; it has been found that polygenic risk scores may provide additional risk stratification for carriers of these mutations, which might enable their physicians to make adequate decisions on the type and timing of breast and prostate cancer risk management.5 In the future, 18F-fluorocholine PET/CT may play an important role in this set of patients.
In conclusion, in our patient, as in the studies of Hugentobler et al1 and Vadrucci et al,218F-flurocholine PET imaging permitted to localize prostate cancer recurrence and contemporarily identify a second unsuspected malignancy in the breast region.