AUA 2017: Survival Among Female Urethral Cancer Patients 2004-2013, a National Cancer Database Analysis

Boston, MA ( Urethral malignancy is a rare oncologic condition; as a result, research in this field often requires large multi-institutional databases, usually retrospective, to help identify patterns and trends in management. The authors add to the retrospective, population based literature using the National Cancer Database, a dataset that reportedly captures more than 70% of incident neoplasms in the United States, comprising more than 29 million unique cancer cases. However, as many studies using the dataset have now pointed out, it is limited by the fact that it only reports overall survival and no cancer-specific outcomes.

In this study, the authors focused on primary urethral neoplasms among women over a 10-year period. They identified 1,088 cases of primary female urethral cancer; the median age at diagnosis was 66 years (IQR 56, 77) and the majority of women were Caucasian (66%).

In terms of histology, adenocarcinoma (AC) was the most common histologic subtype (34%), followed by squamous (SCC) (26%) and urothelial cell carcinoma (UC) (25%). Women with AC were younger (63 years vs 69 for UC and 67 for SCC, p<0.001) and more likely to be African American (56.0 % vs 24.2%, p<0.001).

At the time of diagnosis, 45% of all patients were ≥cT3 and 38% were clinical stage III or higher, highlighting the late stage diagnosis in women. In fact, 16.6% had clinical node positive disease and 8.8% had distant metastatic disease.

They then looked at treated modality. Surgery alone was the most common treatment modality in patients undergoing single-modality therapy. Patients with AC were more likely to be ≥cT3 and more likely to undergo definitive surgery. Patients with SCC were more likely to be treated with primary chemo-radiation; nearly 44% of patients with SCC received radiation therapy during treatment. Patients with cT2-4N0M0 patients – trimodal therapy was found to have the best OS. Receipt of chemotherapy was associated with improved OS in patients with N1 disease.

Median survival for those living was 47 months while 5 year OS was 41%. As mentioned earlier, CSS was not available. As indicated by the higher stage at the time of diagnosis, 5 year OS for AC was worse than SCC or UC (Figure 1) (Log-Rank 0.013). However, this was likely stage related, as on multivariate analysis, after adjusting for clinical TNM stage, race, age, and treatment modality, histology was no longer significantly associated with overall survival (p=0.57).

The authors conclude that patients with AC are more likely to present at a later stage than those with SCC or UC, leading to worse OS; however, 5-year OS is poor regardless of histology.

Limitations / Discussion Points:
1. This data doesn’t provide much new information to the understanding of primary urethral malignancy. The poor prognosis was always known.
2. As cancer-specific outcomes are not known, it is hard to make any conclusions about cancer-care.
3. 15-40% of patients had incomplete staging due to the nature of the database.
4. Location of the disease is not known in the database. Proximal vs. distal urethral cancers behave and managed very differently.

While it utilizes a new dataset to specifically assess female urethral neoplasms, it doesn’t necessary change management at this time. The emphasis on multimodality therapy is important, however.

Presented by: Mary Westerman

Co-Authors: Vidit Sharma, Derek J. Gearman, Matthew K. Tollefson, Stephen A. Boorjian, Deborah J. Lightner, R. Jeffrey Karnes

Institution(s): Mayo Clinic, Rochester, MN

Written By: Thenappan Chandrasekar, MD, Clinical Fellow, University of Toronto
Twitter: @tchandra_uromd

at the 2017 AUA Annual Meeting - May 12 - 16, 2017 – Boston, Massachusetts, USA