PROSTATE CANCER

Highly portable quantitative screening test for prostate-specific antigen at point of care

To provide early warning to populations with a higher incidence of prostate cancer, as well as those with limited access to health care services, researchers have developed a portable and rapid prostate cancer screening kit. The proof-of-concept test, which is inexpensive and accessible, uses a test strip and a small, cube-shaped 1.6-inch reader to quantify prostate-specific antigen (PSA) from a drop of blood in minutes (Current Research in Biotechnology 2021; doi: 10.1016/j.crbiot.2021.11.003). Currently, the study authors noted, most total PSA testing depends on dedicated centralized laboratories that use large, automated analyzers. As a result, longer turnaround times can cause delays in patient care, in addition to increased administration and medical costs. The kit combines a test strip-like what is used for at-home COVID-19 antigen or pregnancy tests-and a highly portable cube-shaped reader. Users would draw a drop of blood and apply it to the test strip, and in about 15 minutes, two lines appear on the strip. The color of the two lines is the result of 150-nanometer gold nanoshells, which greatly enhance the test's sensitivity to detect PSAs and make the lines appear more intense in their presence, according to the researchers. Once the cube reader senses the intensity of the test strip lines, it then calculates and displays a measurement of PSA concentration in the blood. The researchers first optimized and evaluated the performance of the assay with commercially available total PSA calibrators. The initial validation achieved a detection range of 0.5-150 ng/mL. When comparing their test with the IMMULITE analyzer for quantification of total PSA in archived human serum samples, the researchers observed a correlation of 0.95 (p<.0001). "Our point-of-care test has the potential to significantly simplify and accelerate patient care by enabling serum total PSA test while the patient is still in the doctors' office for the consultation," the study authors stated. "This near-patient screening with results available within 20 minutes would enable physicians to quickly decide if additional diagnostic testing with a multiparametric MRI or prostate biopsy is required for the patient." They concluded that this portable, quantitative screening test for PSA has the potential to make prostate cancer screening more accessible, reduce therapeutic turnaround time, streamline clinical care, and direct patient care for both initial screening as well as post-treatment monitoring of patients.

GASTRIC ADENOCARCINOMA

Association of preoperative chemosensitivity with postoperative survival in patients with resected gastric adenocarcinoma

A recent cohort study found that preoperative chemosensitivity was associated with significantly longer survival among patients with resectable gastric adenocarcinoma who received postoperative chemotherapy (JAMA Netw Open 2021; doi:10.1001/jamanetworkopen.2021.35340). To better understand the survival benefit of postoperative chemotherapy, researchers initiated a national, hospital-based cohort study that used data from the National Cancer Database. The study included 2,382 patients with clinical Stage II or III disease who underwent preoperative chemotherapy and curative-intent resection. The majority of patients were men (67%) and the median age of the cohort was 63 years. Among the study participants, 62 percent had refractory disease, 31 percent had sensitive disease, and 7 percent had very sensitive disease. Most patients (64%) did not undergo postoperative chemotherapy. The researchers found that the likelihood of receiving postoperative chemotherapy was significantly lower among patients who were older and had a comorbidity, longer time from chemotherapy initiation to surgery, less sensitivity to preoperative chemotherapy, and longer hospitalization after surgery. The data showed that postoperative chemotherapy was not associated with improved survival in the whole group. Patients with refractory disease had the worst survival compared with those with sensitive disease and very sensitive disease, according to the study authors. Overall, the researchers observed that preoperative chemosensitivity was significantly associated with a survival benefit from postoperative chemotherapy. Patients with sensitive disease who were treated with postoperative chemotherapy lived longer than those who did not, with 5-year survival rates of 73.8 percent and 65 percent, respectively. However, no significant difference in survival was observed among patients with very sensitive or refractory disease who were treated with postoperative chemotherapy when compared to those who did not receive this treatment. "In this cohort study, preoperative chemosensitivity was associated with survival among patients with resectable gastric adenocarcinoma who received postoperative chemotherapy," the study authors concluded. "These findings may help inform future studies to personalize postoperative therapy."

MELANOMA

Relatlimab and nivolumab versus nivolumab in untreated advanced melanoma

Recent results from the Phase II/III RELATIVITY-047 clinical trial demonstrated that the combination of two immune checkpoint inhibitors-relatlimab and nivolumab-doubled the progression-free survival (PFS) benefit among patients with untreated, advanced melanoma when compared to nivolumab alone (N Engl J Med 2022; doi: 10.1056/NEJMoa2109970). In this global, double-blind, randomized trial, the researchers evaluated relatlimab and nivolumab as a fixed-dose combination in comparison to nivolumab alone when administered intravenously every 4 weeks. The primary endpoint was PFS as assessed by blinded independent central review. Between May 2018 and December 2020, 714 patients with untreated, unresectable Stage III or IV melanoma were enrolled across 111 international sites. They were randomized to receive relatlimab and nivolumab or nivolumab alone once every 4 weeks. Among study participants, 60 (8.4%) received prior targeted therapy or immunotherapy as adjuvant therapy at least 6 months prior to recurrence or received interferon 6 weeks before randomization. The median age of included patients was 63, 41.7 percent were female, and 96 percent were White. As of the data cutoff (March 9, 2021), median follow-up was 13.2 months, with 470 patients (65.8%) having discontinued treatment. Disease progression was the top reason for discontinuation. The study authors reported that the median PFS was 10.1 months among patients who received relatlimab plus nivolumab compared with 4.6 months in the nivolumab-only treatment group. At 12 months, PFS was 47.7 percent with relatlimab plus nivolumab and 36 percent with nivolumab alone. The data showed that the survival benefit with relatlimab plus nivolumab was sustained across pre-defined subgroups, including BRAF status, tumor stage, and lactate dehydrogenase levels, as well as LAG-3 and PD-1 expression. Grade 3 or 4 treatment-related adverse events were observed in 18.9 percent of patients in the relatlimab-nivolumab arm compared to 9.7 percent in the monotherapy arm. The most common Grade 3 or 4 events included increased levels of pancreatic and liver enzymes as well as fatigue. The researchers identified no new safety signals and reported that patients rated their health-related quality of life similarly across both treatment arms. The study authors concluded, "the inhibition of two immune checkpoints, LAG-3 and PD-1, provided a greater benefit with regard to progression-free survival than inhibition of PD-1 alone in patients with previously untreated metastatic or unresectable melanoma."