Our results are consistent with those of previous studies [8, 9], indicating an increase of old patients with high-risk bladder cancer. In this study, 47 (31.8%) and 20 (13.5%) patients had PTN and T2DM, and 9 (6.1%) and 6 (4.1%) patients suffered from myocardial infarction and cerebral infarction, respectively. Furthermore, 25 patients (16.9%) were currently undergoing oral anticoagulant therapy, and 30 (20.3%) had a history of smoking. For MIBC patients with multiple comorbidities, several studies have shown that RC had a high cure rate and a low recurrence rate in T2–T4a patients with MIBC [10, 11]. However, the high perioperative complication rate and impact on postoperative quality of life provided numerous patients with MIBC with the unwillingness to undergo RC [12, 13]. Reports show that the 1-month and 3-month major complication rates of RC were 14.4% and 21.7%, respectively [14]. Moreover, the mortality rate after RC gradually increased with age. Previous studies have shown that the mortality rate of patients aged 70–79 years after RC surgery was 5.4% at 3 months, whereas the rate increased to 9.2% in patients over 80 years [15,16,17]. Due to age, comorbidities, treatment toxicity, and subjective factors, increasing MIBC patients cannot undergo RC and remain hopeful for urgent adoption of organ-preserving treatment strategies.

TMT is a recognized treatment strategy for selected patients with MIBC [18, 19]. Fahmy et al. extracted data from 3402 patients treated with TMT and 26,891 patients with RC and observed no significant difference in the 10-year OS (30.9% vs. 35.1%) or DSS (50.9% vs. 57.8%) [20]. However, no large randomized controlled studies have been published on organ-preserving treatment strategies for MIBC. The difference in oncological outcomes between TMT and RC remains unclear, as reflected by the 5-year OS rates ranging from 36 to 74% [21]. Thus screening for the optimal patient population for TMT is challenging.

In this study, we used RPVBT surgery combined with adjuvant chemotherapy to treat patients with single, ≤ 3 cm, and T2 stage MIBC. Our data showed that patients with single, ≤ 3 cm T2 stage MIBC had similar RFS and OS with NMIBC treated with PVBT or patients with T2 stage MIBC who underwent RC. No reports exist on organ-conserving therapy with RPVBT + chemotherapy for patients with T2 stage, < 3 cm bladder cancer; however, a few research results are similar to our conclusions. Gofrit’s study showed that in cisplatin-eligible patients with a tumor diameter ≤ 3 cm, TMT provides an excellent disease-specific survival rate [22]. Giacalone et al. enrolled 475 patients with cT2-T4a MIBC and demonstrated that patients who underwent TMT had high rates of CR and confirmed DSS rates similar to those in RC, and patients with T2 tumor had a better outcome [2]. Kaushik’s comparative analysis showed that the median OS in MIBC patients treated with RC was longer than that in those who underwent TMT (36.2 vs. 24.2 months), and indicated that patients with T3 and T4 stagetumor in the TMT group had decreased OS compared to patients with T2 stage, which may be the selected patients [2]. Polineni’s study reported that selected T2 MIBC was an effective option with OS and DFS comparable to those of patients who underwent RC [23]. Ploussard et al. reported that the cancers best eligible for bladder preservation were those with low-volume T2 disease without in situ carcinoma [24]. Based on previous research and our findings, we believe that T2 stage, single, and tumor sizes of less than 3 cm in diameter are the populations for TMT treatment options.

The RPVBT for patients with MIBC had several technological advantages, as follows: (1) The GreenLight laser could vaporize tumors to the depth of the external fat of the bladder precisely, achieving local “radical.” (2) The fiber emits light laterally at 70°, which makes it easy to treat tumors on the anterior wall, top, and neck of the bladder. The GreenLight laser does not induce bladder perforation caused by the obturator nerve reflex, allowing the surgeon to completely vaporize the tumor. (4) Unlike TURBT, which directly contacts the tumor tissue, the GreenLight laser uses a non-contact method to vaporize tumors, which avoids tumor compression and potentially reduces the chance of tumor dissemination and metastasis. (5) Sealing vessels can prevent tumor cell implantation and transfer through the blood and lymphatic pathways. (6) The combination of postoperative adjuvant chemotherapy and bladder perfusion can reduce the rate of tumor recurrence. (7) RPVBT surgery can be performed in the supine position, which is suitable for patients who cannot undergo a lithotomy.

To address the potential challenge of irrigation fluid extravasation during the procedure, we perform vaporization resection of the tumor and close surrounding blood vessels prior to vaporizing to the extravesical fat, thereby shortening the surgical time after “bladder perforation”. Besides, when vaporizing the bladder muscle layer to the extravesical fat, we reduce the pressure of the irrigation fluid to prevent increased extravasation caused by excessive bladder pressure. To prevent tumor dissemination outside the bladder during RPVBT, we also tale several measures. Firstly, the risk of tumor metastasis is lower with “non-contact” Greenlight laser vaporization resection compared to TURBT. Secondly, by reducing irrigation fluid extravasation outside the bladder, we aim to minimize the risk of extravesical tumor spread. Lastly, after the vaporization resection is complete, we instill sterile water for injection into the bladder to further reduce the risk of tumor seeding.

Our study has certain limitations. First, retrospective studies on this topic are limited. Additionally, this study was a single-center effort, meaning that the enrolled patients were from a specific region. The number of patients enrolled in this study was relatively small, and the follow-up period was short. This highlights the necessity of substantiating our conclusions using larger samples and longer follow-up periods.