Prostate Adenocarcinoma Metastasis to the Rectal Submucosa and Mesorectal Lymph Node on 18 F-PSMA PET/CT

ABSTRACT

We report a case of biopsy-proven prostate cancer metastasis to the rectum and presumed metastasis to a mesorectal lymph node, identified as radiotracer-avid lesions on prostate-specific membrane antigen PET/CT during workup for biochemically recurrent prostate cancer. This case adds to a growing number of atypical sites of metastatic prostate cancer being reported since the approval of prostate-specific membrane antigen PET/CT for staging of prostate cancer.

Long-term outcomes and predictors of early response, late relapse, and survival for patients treated with bispecific LV20.19 CAR T-cells

We previously reported results of a first-in-human trial of bispecific LV20.19 chimeric antigen receptor T-cell (CAR-T) therapy, demonstrating high response rates in patients with relapsed, refractory (R/R) B-cell malignancies. We now report two-year survival outcomes and predictors of early response, late relapse, and survival. Patients from the previously reported phase 1 dose escalation and expansion trial of LV20.19 CAR-T therapy (NCT03019055) treated at target dose of 2.5 × 10⁶ cells/kg (n = 16) were included in this updated analysis. Two-year progression-free survival (PFS) and overall survival (OS) were estimated using Kaplan-Meier method. The relationship of in-vivo CAR-T expansion, tumor burden, and effector: target ratio on early response (day 28) and late relapse (>180 days post-CAR-T) were assessed. Exact log-rank testing was performed to evaluate the impacts of clinical variables on survival outcomes. With a median of 31 months (range 27-40) of follow-up, two-year PFS and OS were 44% and 69%. Median PFS and OS were 15.6 months and not reached, respectively. For CAR-naïve large B-cell lymphoma patients (n = 8), two-year PFS and OS were 50% and 75%. No patient with progression experienced dual target antigen (CD19 or CD20) loss on post-relapse biopsy. Lower in vivo expansion was strongly associated with late relapse. Early treatment response was impeded by high metabolic tumor volume and low effector: target ratio. Bridging therapy and higher absolute lymphocyte count on day of CAR-T infusion were associated with inferior survival outcomes. In conclusion, this initial trial of LV20.19 CAR-T demonstrates a signal for favorable long-term outcomes for patients with R/R B-cell malignancies.

Value of Pretreatment 18F-fluorodeoxyglucose Positron Emission Tomography in Patients With Localized Pancreatic Cancer Treated With Neoadjuvant Therapy

Background:¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) imaging is not routine in patients with localized pancreatic cancer (PC). We evaluated the prognostic value of PET/CT in patients who received neoadjuvant therapy.

Methods: Patients with localized PC underwent pretreatment PET/CT with or without posttreatment (preop) PET/CT. Maximum standardized uptake values (SUV) were classified as high or low based on a cut point of 7.5 at diagnosis (SUV_dx) and 3.5 after neoadjuvant therapy (preoperative; SUV_preop). Preop carbohydrate antigen 19-9 (CA19-9) was classified as normal ( ≤ 35 U/mL) or elevated.

Results: Pretreatment PET/CT imaging was performed on 201 consecutive patients; SUV_dx was high in 98 (49%) and low in 103 (51%). Preop PET/CT was available in 104 (52%) of the 201 patients; SUV_preop was high in 60 (58%) and low in 44 (42%). Following neoadjuvant therapy, preop CA19-9 was normal in 90 (45%) patients and elevated in 111 (55%). Median overall survival (OS) of all patients was 27 months; 33 months for the 103 patients with a low SUV_dx and 22 months for the 98 patients with a high SUV_dx (p = 0.03). Median OS for patients with low SUV_dx/normal preop CA19-9, high SUV_dx/normal preop CA19-9, low SUV_dx/elevated preop CA19-9, and high SUV_dx/elevated preop CA19-9 were 66, 34, 23, and 17 months, respectively (p < 0.0001). OS was 44 months for the 148 (74%) patients who completed all intended neoadjuvant therapy and surgery and 13 months for the 53 (26%) who did not undergo surgery (p < 0.001).

Conclusion: Pretreatment PET/CT avidity and preop CA19-9 are clinically significant prognostic markers in patients with PC.