Editors: Rouzan Karabakhtsian, MD, PhD, professor of pathology and director of the Women’s Health Pathology Fellowship, Albert Einstein College of Medicine, Montefiore Medical Center, Bronx, NY; Shaomin Hu, MD, PhD, staff pathologist, Cleveland Clinic; S. Emily Bachert, MD, associate pathologist, Brigham and Women’s Hospital, Boston; and Amarpreet Bhalla, MD, assistant professor of pathology, Albert Einstein College of Medicine, Montefiore Medical Center.
ISUP consensus conference on issues in bladder cancer: subcategorization of T1 bladder cancer
August 2024—Emerging data suggest a correlation between T1 bladder cancer subcategorization, or substaging, and oncological outcomes. The International Society of Urological Pathology held a 2022 consensus conference on issues in bladder cancer, in Basel, Switzerland, in which it tasked a working group with making recommendations for T1 subcategorization of transurethral bladder resections. To this end, the ISUP developed and circulated a survey to its membership querying approaches for subcategorizing T1 bladder cancer. The survey focused on clinical relevance, pathological reporting, and endorsement of T1 subcategorization in the daily practice of pathology. Approximately 40 percent of respondents to the pre-meeting survey indicated that they do not routinely report the T1 subcategory. The authors, members of the ISUP bladder tumor consensus panel, reviewed literature on bladder T1 subcategorization and screened selected articles for the clinical performance and practicality of T1 subcategorization methods. The literature provided evidence of the clinical rationale for T1 subcategorization. Conference attendees reached a consensus (83 percent agreement) that ISUP should endorse T1 subcategorization of transurethral resections. Semiquantitative T1 subcategorization was favored (37 percent) over histoanatomic methods (four percent). This is in line with findings reported in the literature on the practicality and prognostic impact of semiquantitative methods. However, 59 percent of participants had no preference for either methodology or a combination of both as long as comments in the report briefly stated the applied method, interpretation criteria, and potential limitations. When queried on the reporting of T1 subcategorization, 34 percent of participants were in favor of T1 microinvasive versus T1 extensive and 20 percent were in favor of T1 focal versus T1 nonfocal.
Lopez-Beltran A, Raspollini MR, Hansel D, et al. International Society of Urological Pathology (ISUP) consensus conference on current issues in bladder cancer working group 3: Subcategorization of T1 bladder cancer. Am J Surg Pathol. 2024;48(1):e24–e31.
Correspondence: Dr. Antonio Lopez-Beltran at em1lobea@uco.es or em1lobea@gmail.com
TRPS1 and GATA3 expression in invasive breast carcinoma with apocrine differentiation
The recently identified IHC marker TRPS1 is highly sensitive and specific for invasive breast carcinoma, especially triple-negative breast carcinoma. However, TRPS1 expression in uncommon morphologic subtypes of breast cancer has not been thoroughly studied. The authors conducted a study to investigate the expression of TRPS1 in invasive breast cancer with apocrine differentiation in comparison to the expression of GATA3. Fifty-two invasive breast carcinomas with apocrine differentiation were evaluated for TRPS1 and GATA3 expression by IHC. They comprised 41 triple-negative breast carcinomas and 11 estrogen receptor (ER)-negative, human epidermal growth factor receptor 2 (HER2)-positive cases. Eleven primary triple-negative breast carcinomas without apocrine differentiation but with high androgen receptor (AR) expression were included for comparison. The clinical and pathologic information collected addressed patient age; gender; histologic diagnosis; grade; tumor size; stage; and ER, progesterone receptor, and HER2 status. All tumors were diffusely positive (more than 90 percent) for AR. Triple-negative breast carcinoma with apocrine differentiation had positive TRPS1 expression in 12 percent (five of 41) of cases, whereas GATA3 was positive in all cases. Similarly, HER2+/ER- invasive breast carcinoma with apocrine differentiation showed positive TRPS1 in 18 percent (two of 11) of cases, whereas GATA3 was positive in all cases. In contrast, triple-negative breast carcinoma with strong AR expression but without apocrine differentiation showed TRPS1 and GATA3 expression in 100 percent (11 of 11) of cases. The authors concluded that most ER-/PR-/AR+ invasive breast carcinomas with apocrine differentiation are TRPS1 negative and GATA3 positive, regardless of HER2 status. Therefore, TRPS1 negativity does not exclude breast origin in tumors with apocrine differentiation. A panel of TRPS1 and GATA3 immunostains can be helpful when the tissue origin of such tumors is clinically relevant.
Wang J, Peng Y, Sun H, et al. TRPS1 and GATA3 expression in invasive breast carcinoma with apocrine differentiation. Arch Pathol Lab Med. 2024;148(2):200 –205.
Correspondence: Dr. Qingqing Ding at qqding@mdanderson.org