Related Experiment Video
Updated: Jul 8, 2026
10:27
Testing Targeted Therapies in Cancer using Structural DNA Alteration Analysis and Patient-Derived Xenografts
Published on: July 25, 2020
Progression-Free Survival Effect Sizes in Randomized Controlled Trials of Targeted Cancer Therapies with Positive
Wei Zhang1,2, Wen Yan1,2, Mengyun Chen1,2
1State Key Laboratory of Experimental Hematology, National Clinical Research Center for Blood Diseases, Haihe Laboratory of Cell Ecosystem, Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Tianjin, China.
Acta Haematologica
|July 6, 2026
Summary
Progression-free survival (PFS) improvements in targeted cancer therapies show decreasing effect sizes, potentially indicating a bias in drug approvals. Analysis of randomized controlled trials (RCTs) reveals concerning trends in oncology research.
Area of Science:
- Oncology
- Clinical Trials
- Drug Development
Background:
- Progression-free survival (PFS) is a key endpoint for regulatory approval of cancer therapies.
- The interpretation of PFS benefits in clinical trials requires careful evaluation of effect sizes.
Purpose of the Study:
- To analyze trends in PFS effect sizes for targeted versus conventional cancer therapies in recent randomized controlled trials (RCTs).
- To investigate potential biases in the acceptance of cancer drug approvals based on PFS outcomes.
Main Methods:
- Systematic analysis of 106 RCTs with positive PFS outcomes published between 2020-2023 in leading oncology journals.
- Categorization of RCTs into 'targeted' (n=83) and 'conventional' (n=23) therapies.
- Evaluation of PFS effect sizes using hazard ratio (HR) and PFS increment, analyzing trends over time.
Main Results:
- Among targeted therapies, the 25th-percentile hazard ratio (HR) significantly increased (slope=0.05/year, P=.02).
- The 25th-percentile PFS increment significantly decreased for targeted therapies (slope=-9.1 percentage points/year, P=.03).
- Similar trends were not observed in conventional therapy trials.
Conclusions:
- The study suggests a potential bias towards accepting targeted therapies despite diminishing PFS effect sizes.
- These findings highlight the need for critical assessment of PFS endpoints in cancer drug approvals.
- Further research is warranted to understand the implications for clinical practice and patient outcomes.
Related Concept Videos
01:21Cancer Survival Analysis
Cancer survival analysis focuses on quantifying and interpreting the time from a key starting point, such as diagnosis or the initiation of treatment, to a specific endpoint, such as remission or death. This analysis provides critical insights into treatment effectiveness and factors that influence patient outcomes, helping to shape clinical decisions and guide prognostic evaluations. A cornerstone of oncology research, survival analysis tackles the challenges of skewed, non-normally...
02:57Targeted Cancer Therapies
The targeted cancer therapies, also known as “molecular targeted therapies,” take advantage of the molecular and genetic differences between the cancer cells and the normal cells. It needs a thorough understanding of the cancer cells to develop drugs that can target specific molecular aspects that drive the growth, progression, and spread of cancer cells without affecting the growth and survival of other normal cells in the body.
There are several types of targeted therapies against specific...
There are several types of targeted therapies against specific...
01:20Comparing the Survival Analysis of Two or More Groups
Survival analysis is a cornerstone of medical research, used to evaluate the time until an event of interest occurs, such as death, disease recurrence, or recovery. Unlike standard statistical methods, survival analysis is particularly adept at handling censored data—instances where the event has not occurred for some participants by the end of the study or remains unobserved. To address these unique challenges, specialized techniques like the Kaplan-Meier estimator, log-rank test, and Cox...
02:56Treatment Resistent Cancers
Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...
02:56Treatment Resistant Cancers
Cancer is the second leading cause of death in the United States. A cancer cell is genetically unstable and hence can mutate faster. They can also modify their microenvironment and escape immune surveillance. The difficulties in treating cancer are further compounded by the emergence of rapid resistance to anticancer drugs. The most common ways to attain resistance in cancer cells include alteration in drug transport and metabolism, modification of drug target, elevated DNA damage response, or...
02:07Tumor Progression
Tumor progression is a phenomenon where the pre-formed tumor acquires successive mutations to become clinically more aggressive and malignant. In the 1950s, Foulds first described the stepwise progression of cancer cells through successive stages.
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...
Colon cancer is one of the best-documented examples of tumor progression. Early mutation in the APC gene in colon cells causes a small growth on the colon wall called a polyp. With time, this polyp grows into a benign, pre-cancerous tumor. Further...