COL1A1::PDGFB fusion-associated uterine fibrosarcoma: A case report and review of the literature.

BACKGROUND: Mesenchymal neoplasms of the uterus encompass a diverse group of tumors, with varying characteristics and origins, collectively accounting for 8% of uterine malignancies. The most common variants include uterine leiomyosarcoma, low-grade and high-grade endometrial stromal sarcoma, adenosarcoma, and undifferentiated sarcoma. Clinical presentation is often nonspecific and can lead to delayed diagnosis. Uterine sarcomas are generally aggressive, resulting in poorer prognosis compared to carcinomas. Recent advances in molecular techniques, such as next-generation sequencing (NGS), have led to the identification of new subtypes of uterine sarcomas, including COL1A1::PDGFB fusion-associated fibrosarcoma, which has a specific chromosomal translocation t(17;22)(q22;q13). Imatinib, a tyrosine kinase inhibitor (TKI), is an effective treatment for dermatofibrosarcoma protuberans (DFSP), marked by this translocation. CASE: We present the case of a 42-year-old woman diagnosed with COL1A1::PDGFB fusion-associated uterine fibrosarcoma. The patient underwent total hysterectomy and excision of the tumor, initially misdiagnosed as a low-grade leiomyosarcoma. Subsequent histological examination, immunohistochemistry, and fluorescence in situ hybridization (FISH) confirmed the diagnosis. After 10 months, disease recurrence was detected, and Imatinib therapy was initiated at a dose of 400 mg daily. An allergic reaction led to a temporary discontinuation, but upon resumption with appropriate medication, a positive radiological response was observed. The patient achieved a complete remission after 2 years and is still on Imatinib treatment. CONCLUSIONS: COL1A1::PDGFB fusion-associated uterine fibrosarcoma is an extremely rare mesenchymal neoplasm. In a case we present herein, we treated a patient with imatinib as first-line medical therapy. The patient is currently in complete remission after 37 months from treatment start. To the best of our knowledge, this represents a unique observation. We also provide a detailed literature review of the published cases so far. Prospective case series are needed to further understand the natural history of these tumors and optimize treatment strategies.

[18F]Fluoro-Deoxy-Glucose positron emission tomography to evaluate lymph node involvement in patients with muscle-invasive bladder cancer receiving neoadjuvant pembrolizumab.

BACKGROUND: Data regarding the role of positron emission tomography/computed tomography (PET/CT) to stage lymph nodes in patients receiving neoadjuvant immunotherapy before radical cystectomy are lacking. The aim of this study is to evaluate the role of PET/CT to predict the pathologic lymph node involvement (LNI) in patients with MIBC receiving neoadjuvant pembrolizumab within the PURE-01 trial (NCT02736266). MATERIAL AND METHODS: Three courses of pembrolizumab were administered before radical cystectomy and extended pelvic lymph node dissection in clinical T2-4aN0M0 MIBC based on contrast-enhanced CT scan. LNI was also assessed with PET/CT before and after treatment. PET/CT results were compared with histopathological findings. The ability of baseline and post-therapy PET/CT to evaluate LNI was assessed, and univariate logistic regression analyses were performed. RESULTS: From February 2017 to August 2019, a total of 108 patients and 105 patients had evaluable baseline and post-pembrolizumab scans, respectively. The sensitivity to detect LNI was 27% and 37.5% for pre- and post-pembrolizumab PET/CT, and specificity was 97% and 98%, respectively. In total, 4 of 7 patients (57%) showing baseline FDG-uptake had LNI vs. 11 of 101 (11%) with no baseline uptake. All but 1 of the 7 patients did not respond to pembrolizumab. Both pre- and post-pembrolizumab PET/CT significantly predicted LNI (P = 0.004 and P < 0.001) at univariate analyses. Our results warrant further validation in larger datasets. CONCLUSIONS: PET/CT performance does not justify its use in routine practice for cN0 MIBC. However, our preliminary data revealed opportunities for the use of baseline PET/CT, within clinical trials, to optimally select patients with MIBC who are best suited for neoadjuvant immunotherapy strategies. Validation in larger datasets, as well as a cost analysis, are needed.

Prognostic Role of Early Interim Fluorodeoxyglucose Positron Emission Tomography in Patients With Advanced Seminoma Undergoing Standard Treatment.

BACKGROUND: Patients with advanced seminoma have an exceedingly favorable prognosis. Studies aiming to reduce the total treatment burden and side effects in patients with well-defined disease and very good prognosis are warranted. PATIENTS AND METHODS: In a prospective observational study, patients with advanced stage seminoma were treated with bleomycin, etoposide, and cisplatin (BEP) or EP according to guidelines. Fluorodeoxyglucose with positron emission tomography and computed tomography (FDG-PET/CT) examinations were performed at baseline, after 2 cycles (PET/CT2) in all patients, and after chemotherapy at the physician's discretion. Disease response to treatment assessed by PET/CT was qualitatively evaluated by 2 independent nuclear medicine physicians. Contrast-enhanced CT scans were also performed according to guidelines (at baseline, after treatment, during follow-up). The study's primary endpoint was to evaluate the association between PET/CT2 findings and relapse-free survival. RESULTS: From January 2009 to January 2017, a total of 75 consecutive patients were enrolled, of whom 70 were included for analysis. The clinical disease stage was IIA-B and IIC-III in 40% and 60%, respectively. By local assessment, 46 PET/CT2 scans (65.7%) were reported as negative, and 46% of these patients had stage IIC-III disease. Five-year relapse-free survival of PET/CT2-positive patients was 75% (95% confidence interval, 60-95) compared to 97.8% (95% confidence interval, 93.7-100) of PET/CT2-negative patients (P = .002). In univariate analyses, PET/CT2 was significantly associated with relapse-free survival (P = .02). CONCLUSIONS: No residual FDG uptake after 2 cycles of conventional chemotherapy is prognostic in advanced seminoma, but it may be useful to optimize the standard prognostic risk groups and may be tested within larger prospective clinical trials of chemotherapy deescalation.

Incidence and Clinical Impact of Inflammatory Fluorodeoxyglucose Positron Emission Tomography Uptake After Neoadjuvant Pembrolizumab in Patients with Organ-confined Bladder Cancer Undergoing Radical Cystectomy.

BACKGROUND: Data regarding the incidence and prognostic impact of immune-related imaging changes, assessed by 18[F] fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) scan, in patients receiving immune-checkpoint inhibitors (ICIs) are lacking. We relied on the population of patients enrolled in the PURE-01 study to evaluate such changes. OBJECTIVE: To evaluate the role of PET/CT to visualize the immune-related adverse events (irAEs) following pembrolizumab. DESIGN, SETTING, AND PARTICIPANTS: From February 2017 to August 2019, in 103 patients with nonmetastatic, clinical T2-4aN0M0 bladder cancer, PET/CT scan was performed before and after neoadjuvant pembrolizumab (N = 206 scans), before radical cystectomy. INTERVENTION: PET/CT before and after neoadjuvant pembrolizumab, before radical cystectomy. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We analyzed the occurrence of irAEs, evaluated according to the Common Terminology Criteria for Adverse Events (CTCAE) version 5.0, against the development of inflammatory FDG uptake described at PET/CT (irAEs + PET/CT). Logistic regression analyses evaluated the association between irAEs + PET/CT and the pathological response to pembrolizumab. Kaplan-Meier curves tested their association with progression-free survival (PFS) after pembrolizumab and radical cystectomy. RESULTS AND LIMITATIONS: Forty patients (39%) developed irAEs + PET/CT in several target organs. The most frequent target organs were the thyroid (N = 18), stomach (N = 14), mediastinal lymph nodes (N = 9), and lung (N = 5). These changes were clinically evident in 18 (45%) and were not associated with the pathological response, neither in terms of complete response (ypT0N0, p = 0.07) nor as downstaging to ypT≤1N0 disease (p = 0.1), although ypT0N0 responses were numerically more frequent in patients with irAEs+ PET/CT (47.5% vs 32%). Furthermore, irAE+ PET/CT events were associated with longer, not statistically significant, 24-mo PFS: 88.3% versus 76.5% (p = 0.5). Our results warrant further validation in larger datasets. CONCLUSIONS: We presented unique surrogate data of PET/CT that could help improve our understanding of nonclinically evident effects of ICI administration, especially in patients at the early disease stage. PATIENT SUMMARY: We evaluated the utility of PET/CT to visualize the occurrence of inflammatory changes after pembrolizumab in patients with localized bladder cancer without metastases. After immunotherapy, 39% of the patients developed 18[F] fluorodeoxyglucose uptake consistent of inflammatory changes. Overall, our data improve our knowledge on the effects induced by immunotherapy, which may have a clinical impact at longer follow-up. Take Home Message ● In the PURE-01 study, T2-4N0M0 muscle-invasive bladder cancer patients were staged with fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) before and after pembrolizumab. ● PET/CT after pembrolizumab revealed inflammatory FDG uptake in 39% of patients, but only 45% of these cases of uptake corresponded to clinically evident adverse events. ● The development of inflammatory uptake was associated with a higher pathological complete response rate and longer progression-free survival, although these differences were not statistically significant.

Percutaneous microwave ablation of renal angiomyolipomas in tuberous sclerosis complex to improve the quality of life: preliminary experience in an Italian center.

AIM: To evaluate efficacy, safety and quality of life of the patients with renal angiomyolipomas (AMLs) associated with tuberous sclerosis complex (TSC) treated with percutaneous microwave ablation (MWA). MATERIALS AND METHODS: Nine patients (7 females and 2 males; mean age 27.6 years, range 23-34), with 10 renal AMLs with a mean size of 6.3 cm (range 4.5-8.5) were treated with image-guided percutaneous MWA. Indications for treatment were the risk of rupture/hemorrhage due to size greater than 4 cm and symptomatology; in one case, a previous hemorrhage was the indication for treatment. During follow-up, the volume of the ablated AMLs and its relationship with the relief of symptoms were registered. Technical and clinical success, safety, and quality of life (QOL) were evaluated in a mean follow-up of 9 months (range 3-12). RESULTS: Technical success was obtained in all cases. Clinical success was obtained in all cases; the volume of the ablated AMLs was not related with symptoms relief; all patients referred a significant improvement in their QOL, with a regularization of daily activities. There were no major procedural complications or delayed adverse events. A small self-limited post-procedural subcapsular hematoma was registered. Post-ablation syndrome was registered in 5 cases and was self-limited in all cases. CONCLUSIONS: Symptoms relief, lower risk of hemorrhage and a normalized QOL were obtained in all patients with a safe and mini-invasive procedure.

Role of pretreatment 18F-FDG PET/CT parameters in predicting outcome of non-endemic EBV DNA-related nasopharyngeal cancer (NPC) patients treated with IMRT and chemotherapy.

PURPOSE: To evaluate the prognostic role of pretreatment 18F-FDG PET/CT metabolic parameters in non-endemic Epstein-Barr Virus (EBV DNA)-related nasopharyngeal cancer (NPC) patients treated with curative intensity-modulated radiation therapy (IMRT) with or without chemotherapy (CHT). MATERIALS/METHODS: We retrospectively reviewed clinical data of 160 consecutive non-metastatic NPC patients who received IMRT with or without CHT. Forty-nine out of 160 patients that underwent whole body 18F-FDG PET/CT at our institution for disease staging with a minimum follow-up to 12 months were included in this study. We evaluated the relationship between maximum and mean standardized uptake values (SUVmax and SUVmean, respectively), metabolic tumor volume and total lesion glycolysis (TLG) of primary tumor and cervical lymph nodes with disease-free survival (DFS) and overall survival (OS). We also investigated the prognostic role of clinical variables such as age, disease stage, plasma EBV DNA load (copies/ml), gross tumor volume of primary tumor and lymph nodes. RESULTS: Median follow-up was 55 months. Two- and 5-year OS were 95.8% and 90.5%, respectively, while DFS was 83.4% at both time points. SUVmax of primary tumor ≥ 18.8 g/ml and primary tumor TLG ≥ 203.1 g were significant prognostic factors of worse OS. Furthermore, stages IVB and EBV DNA load ≥ 3493 copies/ml were significantly associated with lower DFS. No correlation was found between PET parameters and plasma EBV DNA load. CONCLUSION: Even in a limited series, our data suggested that SUVmax, SUVmean and TLG of primary tumor could predict a poor outcome in NPC patients also in non-endemic area hypothesizing their use for refinement of prognostication.

Perioperative Bevacizumab-based Triplet Chemotherapy in Patients With Potentially Resectable Colorectal Cancer Liver Metastases.

BACKGROUND: In colorectal cancer liver metastases (CRCLM), bevacizumab-based neoadjuvant strategies provide increased pathologic response. We aimed at assessing the activity of perioperative capecitabine, oxaliplatin, irinotecan, and bevacizumab (COI-B regimen) in patients with potentially resectable CRCLM, and investigating biomarkers for early prediction of pathologic response. PATIENTS AND METHODS: This was a single-center phase II study enrolling patients with liver-limited, borderline resectable disease and/or high-risk features. Patients received 5 preoperative and 4 postoperative cycles of biweekly COI-B (irinotecan 180 mg/m2 and bevacizumab 5 mg/Kg on day 1, oxaliplatin 85 mg/m2 on day 2, and capecitabine 1000 mg/m2 twice a day on days 2 to 6). The primary endpoint was pathologic response rate in the intention-to-treat population. A Simon 2-stage design was adopted to detect an increase from 30% to 50% with a power of 90%. Dynamic imaging biomarkers (early tumor shrinkage [ETS], deepness of response, maximum standardized uptake volume [SUVmax]/regression index) and next generation sequencing data were explored as surrogates. RESULTS: From June 2013 to March 2017, 46 patients were enrolled. Pathologic response was achieved in 63% patients (endpoint met), and responders achieved significantly better survival outcomes with respect to non-responders. The most frequent grade 3/4 adverse events were diarrhea and neutropenia (8.7%) in the preoperative phase and thromboembolic events (5.9%) in the postoperative phase. ETS and lower SUV-2 were significantly associated with pathologic response. CONCLUSION: The COI-B regimen is a feasible and highly active perioperative strategy in patients with molecularly unselected, potentially resectable CRCLM. ETS and SUV-2 have a promising role as imaging-based biomarkers for pathologic response.

Intra-caval Percutaneous Radiofrequency Ablation for a Neuroendocrine Tumor (NET) Metastasis in Transplanted Liver.

Less than 1% of patients with liver metastases from neuroendocrine tumors (NETs) are susceptible to liver transplantation. We report a case of a patient transplanted 13 years ago for NET metastases, with a lesion histologically proved for NET metastasis located at the cava vein anastomosis. He was treated with percutaneous radiofrequency ablation (RFA) after a first failed attempt of endovascular approach. The vascular heat sink, which RFA is susceptible to, was considered an advantage in this case, since it restricted the propagation of heat only to the tissue located in the very proximity of the RFA antenna, protecting the inferior vena cava vessel walls. This positive result may suggest an additional use of RFA in selected challenging cases.

Preoperative Capecitabine, Oxaliplatin, and Irinotecan in Resectable Gastric or Gastroesophageal Junction Cancer: Pathological Response as Primary Endpoint and FDG-PET Predictions.

OBJECTIVES: This phase II trial was aimed at assessing the safety and activity of capecitabine, oxaliplatin, and irinotecan (COI regimen) as a preoperative treatment for resectable gastric cancer (GC) or gastroesophageal junction (GEJ) cancer. METHODS: Patients affected by T3-T4/N0-N+/M0 GC/GEJ cancer were treated with the COI regimen for 4 cycles followed by restaging and gastroresection with D2 lymphadenectomy. Four postoperative cycles were scheduled. The primary endpoint was pathological response rate according to Becker et al. [Cancer 2003;98:1521-1530]. The potential role of fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) as a predictive biomarker of pathological tumor response was assessed in a subgroup of 19 evaluable patients. RESULTS: Between January 2011 and October 2015, a total of 40 patients were enrolled. After the preoperative phase, 36 out of 40 patients (90%) were considered eligible for surgery: 12 patients (30%) achieved a pathological response. The most frequent grade 3/4 adverse events were diarrhea (27%), nausea (25%), and fatigue (17%). Grade 3 neutropenia occurred in 7.5% of patients. A lower standard uptake value at baseline FDG-PET/CT was associated with pathological response. CONCLUSION: COI combination is active with a manageable toxicity profile in patients with resectable GC or GEJ cancer. FDG-PET/CT imaging as a surrogate biomarker of pathological response in this setting appears fascinating but should be further investigated.

Interim (18)F-Fluorodeoxyglucose Positron Emission Tomography for Early Metabolic Assessment of Response to Cisplatin, Etoposide, and Bleomycin Chemotherapy for Metastatic Seminoma: Clinical Value and Future Directions.

BACKGROUND: In patients with metastatic seminoma, designing a risk-adapted strategy that may help personalize the burden of treatment and follow-up is required. PATIENTS AND METHODS: Patients who were administered cisplatin, etoposide, and bleomycin (PEB) were staged at baseline with computed tomography (CT), positron emission tomography (PET), and serum tumor markers. Restaging was then performed with PET after 2 cycles of PEB (PET2) and with CT after 3 to 4 cycles of treatment. The 20% cutoff of maximal standardized uptake value (SUVmax) changes and Response Evaluation Criteria in Solid Tumors (RECIST, version 1.1) criteria were applied to define the response. The Wilcoxon rank sum test was used to analyze the association between metabolic response and the shrinkage of target lesions. RESULTS: Between February 2009 and November 2013, 37 patients were enrolled. After 2 cycles of PEB, 27 patients (72.9%; 95% confidence interval [CI], 55.8-86.2) had a metabolic complete response (CR) and 10 patients had a partial response (PR; 27%; 95% CI, 13.8-44.1). A significant association was found between PET2 response and baseline (P = .003), final diameter (P < .001), and percentage of tumor shrinkage (P = .014) of target lesions. After 18 months' (interquartile range [IQR], 13-23) median follow-up, 2 patients with PET2 PR had relapsed disease; none of those with a CR had relapsed disease. CONCLUSIONS: A significant association was found between early metabolic response and tumor shrinkage in patients with advanced seminoma. Patients achieving a PET2 CR could be predicted not to need additional treatment after PEB, and simplifying their follow-up should be an end point. PET2 might also identify difficult to treat cases at an early stage.

FDG-PET/CT to predict optimal primary cytoreductive surgery in patients with advanced ovarian cancer: preliminary results.

AIMS AND BACKGROUND: Primary cytoreductive surgery (CRS) has a significant impact on prognosis in epithelial ovarian cancer (EOC). Patient selection is important to recognize factors limiting optimal CRS and to avoid unnecessary aggressive surgical procedures. We evaluated the contribution of fluorodeoxyglucose (FDG)-positron emission tomography (PET)/computed tomography (CT) in the presurgical identification of disease sites that may preclude EOC cytoreducibility. METHODS: Patients with suspected EOC underwent 18F-FDG-PET/CT within 20 days before debulking surgery. The PET/CT results were compared with surgical findings and postsurgery histopathology in order to assess the diagnostic value. RESULTS: Between August 2013 and January 2014, 29 patients were evaluated. The histopathology showed 23 EOC and 6 benign tumors. The FDG-PET/CT was positive (maximum standardized uptake value [SUVmax] 11.3 ± 5.4) in 21/23 (91%) patients with EOC and provided 2 false-negatives (1 mucinous and 1 clear cell carcinoma; SUVmax ≤2.8). The FDG-PET/CT was true-negative (SUVmax 2.2 ± 1.6) in 4 out of 6 patients (67%). False-positive FDG-PET results were obtained in 2 cellular fibromas (SUVmax 4.8 and 5.6). The sensitivity, specificity, and accuracy of PET/CT to characterize ovarian masses were 91%, 67%, and 86%, respectively. Among the 21 FDG-PET/CT-positive EOC, we detected factors limiting optimal CRS in 6 cases (29%): 4 hepatic hilum infiltration and 2 root mesentery involvement, confirmed at surgical exploration. The FDG-PET did not find limiting factors in the remaining 15 patients (71%) in whom optimal CRS was obtained. CONCLUSIONS: Fluorodeoxyglucose-PET/CT shows high sensitivity but suboptimal specificity in the characterization of ovarian masses. However, PET/CT may play a role in noninvasively selecting patients with EOC who can benefit from primary CRS.

¹8F-FLT PET/CT as an imaging tool for early prediction of pathological response in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy: a pilot study.

PURPOSE: We evaluated whether (18)F-3'-deoxy-3'-fluorothymidine positron emission tomography (FLT PET) can predict the final postoperative histopathological response in primary breast cancer after the first cycle of neoadjuvant chemotherapy (NCT). METHODS: In this prospective cohort study of 15 patients with locally advanced operable breast cancer, FLT PET evaluations were performed before NCT, after the first cycle of NCT, and at the end of NCT. All patients subsequently underwent surgery. Variables from FLT PET examinations were correlated with postoperative histopathological results. RESULTS: At baseline, median of maximum standardized uptake values (SUVmax) in the groups showing a complete pathological response (pCR) + residual cancer burden (RCB) I, RCB II or RCB III did not differ significantly for the primary tumour (5.0 vs. 2.9 vs. 8.9, p = 0.293) or for axillary nodes (7.9 vs. 1.6 vs. 7.0, p = 0.363), whereas the Spearman correlation between SUVmax and Ki67 proliferation rate index was significant (r = 0.69, p < 0.001). Analysis of the relative percentage change of SUVmaxin the primary tumour (∆SUVTmax(t1)) and axillary nodes (∆SUVNmax(t1)) after the first NCT cycle showed that the power of ∆SUVTmax(t 1) to predict pCR + RCB I responses (AUC = 0.91, p < 0.001) was statistically significant, whereas ∆SUVNmax(t1) had a moderate ability (AUC = 0.77, p = 0.119) to separate subjects with ΔSUVTmax(t1) > -52.9 % into two groups: RCB III patients and a heterogeneous group that included RCB I and RCB II patients. A predictive score µ based on ΔSUVTmax(t1) and ΔSUVNmax(t1) parameters is proposed. CONCLUSION: The preliminary findings of the present study suggest the potential utility of FLT PET scans for early monitoring of response to NCT and to formulate a therapeutic strategy consistent with the estimated efficacy of NCT. However, these results in a small patient population need to be validated in a larger independent cohort.

Gingival metastasis as first sign of multiorgan dissemination of epithelioid malignant mesothelioma.

INTRODUCTION: Metastatic malignant mesothelioma to the oral cavity is extremely rare. They are more common in the jaw bones than the soft tissue. Occurrence of the malignant disease typically carries an average survival rate of 9-12 months METHODS: : Thirteen patients underwent neoadjuvant chemotherapy and radical pleurectomy decortication, followed by radiotherapy from August 2012 to September 2013. Patients were followed up with computed tomography of the chest and the abdomen every 3 months. All patients were followed up until February 2014. RESULTS: In January 2014, 11 patients were still alive with a median survival of 11 months, eight patients developed a recurrence and two patients died at 8 and 9 months after surgery. After 1 year from macroscopic radical pleurectomy decortication, a 68-year-old man suffered from gingival mass turned out to be a metastatic deposit of biphasic malignant mesothelioma as first sign of multiorgan recurrence. The patient underwent chemotherapy and local radiotherapy in the oral cavity. CONCLUSIONS: This case points out the relevance of biopsy to all new growing lesions, even in uncommon anatomical sites, whenever a history of mesothelioma is on record.

Interim fluorine-18 fluorodeoxyglucose positron emission tomography for early metabolic assessment of therapeutic response to chemotherapy for metastatic transitional cell carcinoma.

BACKGROUND: The prognostic impact of early metabolic response by fluorine-18 fluorodeoxyglucose positron emission tomography (FDG-PET) after 2 cycles of first-line chemotherapy is still unrecognized in metastatic transitional cell carcinoma (TCC). PATIENTS AND METHODS: Patients with metastatic TCC receiving the modified combination of methotrexate, vinblastine, doxorubicin, and cisplatin (MVAC), according to institutional protocol, underwent computed tomography (CT) and FDG-PET imaging at baseline, a restaging with PET imaging after 2 cycles only (PET2), and a CT (± FDG-PET) scan at the end of treatment and during follow-up. Progression-free survival (PFS) and overall survival (OS) were estimated with the Kaplan-Meier method; univariate (UVA) and multivariate (MVA) Cox models were fitted. Prespecified variables were the presence of visceral metastases, nodal or soft tissue disease, and early PET response. RESULTS: In the period from May 2010 to October 2012, 31 patients with Eastern Cooperative Oncology Group performance status 0 received the modified MVAC regimen every 3 weeks. In all, 6 patients (19.3%) had a complete response (CR) and 17 (54.8%) a partial metabolic response (PR), 4 had stable disease (SD), and 4 progressed. PET2 responders had a median PFS of 8 months (95 % CI, 7-11 mo) compared with 3 months (95 % CI, 2-5 mo) of patients without response (P = .024). They also had a significant benefit in 8-month PFS (P < .001 via Klein test) and 15-month OS (P = .016). PET2 response was significant for PFS in both UVA and MVA Cox models (P = .027 and P = .023, respectively). CONCLUSION: PET response after 2 cycles of first-line chemotherapy, compared with detection by early CT, was associated with longer PFS and OS in advanced TCC and warrants further investigation in the field.