Bladder cancer

Bladder cancer

Epidemiology:

Bladder cancer represents a significant public health concern, ranking as the tenth most common cancer globally, with approximately 573,000 new cases annually and a persistent high mortality rate despite therapeutic advancements ¹. Spontaneous remission (SR) in bladder cancer is a rare phenomenon, noted in fewer than 1% of cases, making it one of the most elusive occurrences in oncology ². Predominantly, SR is defined as an unexpected and complete resolution of tumors in the absence of any form of treatment, and documented cases primarily involve localized urothelial carcinomas ^3,4.

Clinical Characteristics:

To date, only a single well-documented case of spontaneous regression (SR) involving bladder cancer has been reported. This case underscores the exceptional rarity of SR in bladder neoplasms and highlights the unpredictable nature of regression within urothelial malignancies. The patient’s age and sex were not reported, but the regression occurred at the primary bladder site following initial evidence of extensive neoplastic involvement. See Table 1 below for further information.

Histological Characteristics:

Among the reviewed cases, the tumor origin was strictly confined to the bladder, with remission observed exclusively at the same primary site. Reports involving non-urothelial tumors or bladder-adjacent conditions were excluded to maintain diagnostic accuracy and ensure that only true instances of spontaneous remission in bladder carcinoma were included.

Proposed Contributing Mechanisms:

Proposed mechanisms for remission were not clearly defined in this case, with the available information suggesting only a possible role of immune-mediated processes. However, no definitive cause of the spontaneous regression was identified.

Site and Extent of Remission:

The documented case demonstrated complete spontaneous remission localized to the bladder, with follow-up showing no recurrence for 18 months. Although the underlying mechanism was not definitively established, an immune-mediated process was suggested. This case highlights that spontaneous remission, while exceptionally rare in bladder malignancies, may occasionally result in meaningful and sustained disease regression.

Table 1: Bladder cancer SR Cases and Clinical Characteristics

References:

1. Salehi A., Saleh K., Rahimi M., Golparian M., & Tarokhian A. Development and external validation of machine learning models to predict postoperative transitional cell carcinoma mortality: a retrospective study.. 2024. doi:10.21203/rs.3.rs-4874784/v1
2. Nishimura K., Okada Y., Okada K., et al. Spontaneous regression of pulmonary metastasis from renal pelvic cancer. Urol Int. 1987;42(6):461-463. doi:10.1159/000282017
3. Mitchell R., Kaur A., Kenne F., Khan A., & Zafar W. Spontaneous regression of metastatic lesions of adenocarcinoma of the gastro-esophageal junction. Cureus. 2021. doi:10.7759/cureus.18784
4. Shrestha A., Regmi A., Rana A., et al. Histomorphological pattern of lesions of cystoscopic bladder biopsies in a tertiary center in nepal- a retrospective descriptive study. J Pathol Nep. 2022;12(2):1913-1916. doi:10.3126/jpn.v12i2.46081
5. Murray, N. P., Fuentealba, C., Salazar, I., Salazar, A., Lopez, M. A., & Minzer, S. (2018). Transitory Spontaneous Remission of Myelodysplasia in an Elderly Man while Receiving Intravesical Bacillus Calmette-Guérin for Bladder Cancer: A Case Report and Review of the Literature. Case reports in hematology, 2018, 9750532. https://doi.org/10.1155/2018/9750532
6. Brunschwig, A. 1963. Spontaneous Regression of Cancer. Surgery 53(4): Apr 1963; 423-431
7. Everson, T. C. 1967. Spontaneous Regression of Cancer. Progress in Clinical Cancer 3: 1967; 79-95
8. Decourcy, J. L. 1933. The Spontaneous Regression of Cancer. Journal of Medicine (Clinical, Experimental and Theoretical) 14: May 1933; 141-146
9. Charles C. Thomas Publisher, Springfield, Illinois, 1966; 99 pages
10. Roxburgh, D. 1935. Spontaneous Regression of Cancer. British Medical Journal 1: Jan 5 1935; 39
11. Franklin, C. I. V. 1982. Spontaneous Regression in Cancer. Prolonged Arrest of Cancer, BA Stoll (ed), John Wiley & Sons Ltd : 1982; Chapter 5, 103-116
12. Connecticut Medicine 54(4): Apr 1990; 179-182. https://doi.org/10.1007/s13126-012-0040-y
13. Smith & Herr, 1980. Spontaneous Regression of Pulmonary Metastases from Transitional Cell Carcinoma. Cancer 46(6): Sept 15 1980; 1499-1502