Approaching clinical problems in prostate cancer radiotherapy using the number needed to treat (NNT) technique

Benefits and risks of antihypertensive medication in adults with different systolic blood pressure: A meta-analysis from the perspective of the number needed to treat

Background

The blood pressure (BP) threshold for initial pharmacological treatment remains controversial. The number needed to treat (NNT) is a significant indicator. This study aimed to explore the benefits and risks of antihypertensive medications in participants with different systolic BPs (SBPs), and cardiovascular disease status from the perspective of the NNT.

Methods

We conducted a meta-analysis of 52 randomized placebo-controlled trials. The data were extracted from published articles and pooled to calculate NNTs. The participants were divided into five groups, based on the mean SBP at entry (120–129.9, 130–139.9, 140–159.9, 160–179.9, and ≥180 mmHg). Furthermore, we stratified patients into those with and without cardiovascular disease. The primary outcomes were the major adverse cardiovascular events (MACEs), and adverse events (AEs) leading to discontinuation.

Results

Antihypertensive medications were not associated with MACEs, however, it increased AEs, when the SBP was <140 mmHg. For participants with cardiovascular disease or at a high risk of heart failure and stroke, antihypertensive treatment reduced MACEs when SBP was ≥130 mmHg. Despite this, only 2–4 subjects had reduced MACEs per 100 patients receiving antihypertensive medications for 3.50 years. The number of individuals who needed to treat to avoid MACEs declined with an increased cardiovascular risk.

Conclusion

Pharmacological treatment could be activated when SBP reaches 140 mmHg. For people with cardiovascular disease or at a higher risk of stroke and heart failure, 130 mmHg may be a better therapeutic threshold. It could be more cost-effective to prioritize antihypertensive medications for people with a high risk of developing cardiovascular disease.

Comparison of different adjuvant therapies for 9 resectable cancer types

PURPOSE

The objective of this study was to compare the clinical benefit across adjuvant therapies for cancer treatment, including adjuvant imatinib, and to quantify the results using the number-needed-to-treat (NNT) approach.

METHOD

We reviewed studies meeting the following criteria: 1) US and European randomized clinical trial populations consisting of patients with cancer who underwent surgical resection of the primary tumor and were considered cancer free; 2) comparators were either placebo or no treatment; and 3) recurrence-free survival (RFS) and overall survival (OS) rates were reported and showed benefit with the experimental treatment. The NNT was calculated as the inverse of the difference in event rate between the study groups in each trial.

RESULTS

We identified 26 adjuvant treatment trials in 9 cancer types. With longer follow-up (3 years vs 1 year), 62.5% of treatments compared with placebo showed a decreased RFS NNT, including imatinib (7 vs 4). The largest relative decrease in RFS NNT over time was 91% (with trastuzumab or cyclophosphamide therapy). Approximately 25% of the treatments resulted in an increase in RFS NNT over time. The RFS NNT for imatinib was lower than that for all other treatments at 3 years of follow-up and lower than that for all but 2 treatments at 1 year. At both year 1 and year 3, the NNT for OS ranged from 6 to 100. Imatinib had an OS NNT of 31 at 3 years.

CONCLUSION

With longer follow-up duration, most adjuvant cancer treatments showed a decreased NNT. Imatinib had one of the lowest NNTs among the adjuvant treatments at 1 and 3 years of follow-up using the RFS data.

The role of indium-111 radioimmunoscintigraphy in post-radical retropubic prostatectomy management of prostate cancer patients

Indium-111 radioimmunoscintigraphy (RIS) has an increasing role in the treatment of prostate cancer and is most commonly performed at this disease site using labeled monoclonal antibody against prostate-specific membrane antigen. There are many limitations of RIS, including low spatial resolution, low diagnostic yield and limited availability. Despite these limitations, the efficacy of RIS has been demonstrated in many clinical studies, including multi-institutional investigations. The highest sensitivity and specificity of RIS appears to be in the post-radical retropubic prostatectomy (post-RRP) setting. RIS has recently been explored for its role in clinical radiotherapy decision-making, and was found to have a significant impact in selecting patients for radiotherapy and for the general radiotherapy treatment volume definition. RIS has also recently been explored for its role in radiotherapy planning and was found to impact clinical target volume design. However, manual editing of the RIS volume is still necessary when projected into the radiotherapy-planning scan, as there is often overlap in the RIS-defined uptake regions with normal structures (rectum, bladder and symphysis bone marrow). The impact of RIS on biochemical control has been explored, with studies in this area yielding conflicting results. It appears that the maximum impact of RIS is possible when areas of labeled antibody uptake regions are co-registered with the radiotherapy-planning computed tomography scan. The larger RIS-guided target volumes do not appear to be prohibitive in increasing radiotherapy-related toxicity. Future directions of the use of RIS for post-RRP prostate cancer are discussed.