We report an ultrasensitive time-resolved immunofluorometric assay (TRIFA) for prostate-specific antigen (PSA). The assay is an improvement of our previous report (Clin Chem 1993;39:2108-14) and includes the utilization of two monoclonal antibodies and a one-step incubation period, which greatly reduces analysis time. The new method demonstrates a superior lower analytical limit of detection (< or = 1 ng/L), a wide dynamic range, absence of a hook effect at 10(6) ng/L PSA, and equimolarity for free PSA and PSA-antichymotrypsin complex. Also, we have compared several aspects of our TRIFA with a commercially available third-generation assay (Immulite). An evaluation of breast tumor cytosol extracts from 315 patients shows PSA immunoreactivity > 15 ng/g of total protein in 28% and 23% by TRIFA and Immulite analysis, respectively. Both methods demonstrate a significant association between breast tumor PSA immunoreactivity and progesterone and estrogen receptor positivity (P <0.001). Analysis of serum samples obtained for monitoring of postradical prostatectomy patients reveals significant PSA changes at concentrations undetectable by conventional methods. The significance of these results as well as the potential applications of ultrasensitive PSA assays in breast and prostate cancers are discussed.

IMPORTANCE Definitive chemoradiation for anal cancer is effective but may be associated with toxic effects, and some patients may not be able to complete the planned treatment. Identifying factors associated with treatment interruption and noncompletion is important to target quality improvement efforts. OBJECTIVE To identify rates of chemoradiation treatment interruption or noncompletion and factors associated with this among patients with anal cancer treated in routine clinical practice. DESIGN, SETTING, AND PARTICIPANTSIn this population-based, retrospective cohort study, the Ontario Cancer Registry was used to identify all incident cases of squamous cell anal cancer treated with curative-intent radiation from 2007 to 2015 in Ontario, Canada. Final analysis of data was performed on August 9, 2019.EXPOSURES Curative-intent radiation therapy. MAIN OUTCOMES AND MEASURESTreatment interruption was defined as more than 7 days between fractions of radiation. Radiation completion was defined as receipt of 45 Gy or more and 25 fractions of radiation. Chemoradiation completion was defined as radiation completion and 2 doses of combination chemotherapy. Associations between patient factors and treatment interruption and noncompletion were estimated with log-binomial models. Cox proportional hazard models were used to estimate the association of treatment interruption or noncompletion with all-cause death, cancer-specific death, and the combined outcome of colostomy or death. RESULTSOverall, 1125 patients with stage I-III anal cancer were treated with curative-intent radiation. Treatment interruptions occurred in 262 (23%). Radiation and chemoradiation noncompletion occurred in 199 (18%) and 280 (25%), respectively. No associations were found to correlate with an increased risk of treatment interruption. Patients older than 70 years were less likely to complete chemoradiation (risk ratio [RR], 0.60; 95% CI, 0.52-0.70), compared with those younger than 50 years. Patients with a higher number of comorbidities were also less likely to complete chemoradiation (RR, 0.70; 95% CI, 0.51-0.95). Patients who did not complete chemoradiation had a higher risk of requiring salvage abdominoperineal resection (

Our qualitative findings suggest that there may be a role for incorporating patient-reported outcome measure assessment tools like EPIC-26 routinely into clinical practice. However, further qualitative and quantitative research is required in order to assess the impact of patient-reported outcome information on communication, patient and clinician satisfaction, and how these and other related outcomes can be used for guiding treatment decision-making.

No abstract