Objective: To test the efficacy of screening by clinical breast examination in downstaging breast cancer at diagnosis and in reducing mortality from the disease, when compared with no screening.Design: Prospective, cluster randomised controlled trial.Setting: 20 geographically distinct clusters located in Mumbai, India, randomly allocated to 10 screening and 10 control clusters; total trial duration was 20 years (recruitment began in May 1998; database locked in March 2019 for analysis).Participants: 151 538 women aged 35-64 with no history of breast cancer.Interventions: Women in the screening arm (n=75 360) received four screening rounds of clinical breast examination (conducted by trained female primary health workers) and cancer awareness every two years, followed by five rounds of active surveillance every two years. Women in the control arm (n=76 178) received one round of cancer awareness followed by eight rounds of active surveillance every two years.Main outcome measures: Downstaging of breast cancer at diagnosis and reduction in mortality from breast cancer.Results: Breast cancer was detected at an earlier age in the screening group than in the control group (age 55.18 (standard deviation 9.10)v56.50 (9.10); P=0.01), with a significant reduction in the proportion of women with stage III or IV disease (37% (n=220)v47% (n=271), P=0.001). A non-significant 15% reduction in breast cancer mortality was observed in the screening arm versus control arm in the overall study population (age 35-64; 20.82 deaths per 100 000 person years (95% confidence interval 18.25 to 23.97)v24.62 (21.71 to 28.04); rate ratio 0.85 (95% confidence interval 0.71 to 1.01); P=0.07). However, a post hoc subset analysis showed nearly 30% relative reduction in breast cancer mortality in women aged 50 and older (24.62 (20.62 to 29.76)v34.68 (27.54 to 44.37); 0.71 (0.54 to 0.94); P=0.02), but no significant reduction in women younger than 50 (19.53 (17.24 to 22.29)v21.03 (18.97 to 23.44); 0.93 (0.79 to 1.09); P=0.37). A 5% reduction in all cause mortality was seen in the screening arm versus the control arm, but it was not statistically significant (rate ratio 0.95 (95% confidence interval 0.81 to 1.10); P=0.49).Conclusions: These results indicate that clinical breast examination conducted every two years by primary health workers significantly downstaged breast cancer at diagnosis and led to a non-significant 15% reduction in breast cancer mortality overall (but a significant reduction of nearly 30%in mortality in women aged ≥50). No significant reduction in mortality was seen in women younger than 50 years. Clinical breast examination should be considered for breast cancer screening in low and middle income countries.Trial registration: Clinical Trials Registry of India CTRI/2010/091/001205; ClinicalTrials.govNCT00632047.

Most patients with cancer receive chemotherapy. Unfortunately, chemotherapy is associated with a number of potentially life-threatening side effects. There is a need to ameliorate chemotoxicity to improve therapeutic outcomes and quality of life. Chemotoxicity arises from systemic DNA damage and inflammation in healthy cells due to chemotherapy drugs. Traditionally, these processes are believed to be caused by the direct death of normal cells by chemotherapeutic drugs. However, new research has challenged this dogma by suggesting that chemotoxicity is a secondary effect associated with the release of cell-free chromatin particles (cfChPs) from cells subjected to drug-induced death. Released cfChPs can freely enter into bystander healthy cells to inflict double-strand (dsDNA) breaks and activate inflammatory and apoptotic pathways. The drug-induced cell death and cfChPs release have cascading effects that exaggerate and prolong chemotoxicity. Furthermore, evidence has emerged from laboratory and preclinical studies, and two phase II clinical trials, indicating that chemotoxicity can be minimised by deactivating cfChPs. Three cfChPs-deactivating agents have been identified, of which the nutraceutical combination resveratrol and copper (R–Cu)—easily administered orally and with little toxicity—is the agent of choice for human therapeutic use. This article aims to provide practising medical oncologists with a perspective on this emerging research on chemotoxicity and its prevention and its potential implications for the future. Well-designed randomised clinical trials will be necessary to establish the true clinical value of these findings in day-to-day practice.

Bystander cells of the tumor microenvironment show evidence of DNA damage and inflammation that can lead to their oncogenic transformation. Mediator(s) of cell–cell communication that brings about these pro-oncogenic pathologies has not been identified. We show here that cell-free chromatin (cfCh) released from dying cancer cells are the key mediators that trigger both DNA damage and inflammation in the surrounding healthy cells. When dying human cancer cells were cultured along with NIH3T3 mouse fibroblast cells, numerous cfCh emerged from them and rapidly entered into nuclei of bystander NIH3T3 cells to integrate into their genomes. This led to activation of H2AX and inflammatory cytokines NFκB, IL-6, TNFα and IFNγ. Genomic integration of cfCh triggered global deregulation of transcription and upregulation of pathways related to phagocytosis, DNA damage and inflammation. None of these activities were observed when living cancer cells were co-cultivated with NIH3T3 cells. However, upon intravenous injection into mice, both dead and live cells were found to be active. Living cancer cells are known to undergo extensive cell death when injected intravenously, and we observed that cfCh emerging from both types of cells integrated into genomes of cells of distant organs and induced DNA damage and inflammation. γH2AX and NFκB were frequently co-expressed in the same cells suggesting that DNA damage and inflammation are closely linked pathologies. As concurrent DNA damage and inflammation is a potent stimulus for oncogenic transformation, our results suggest that cfCh from dying cancer cells can transform cells of the microenvironment both locally and in distant organs providing a novel mechanism of tumor invasion and metastasis. The afore-described pro-oncogenic pathologies could be abrogated by concurrent treatment with chromatin neutralizing/degrading agents suggesting therapeutic possibilities.

Radiation-induced bystander effect (RIBE) is a poorly understood phenomenon wherein non-targeted cells exhibit effects of radiation. We have reported that cell-free chromatin (cfCh) particles that are released from dying cells can integrate into genomes of surrounding healthy cells to induce DNA damage and inflammation. This raised the possibility that RIBE might be induced by cfCh released from irradiated dying cells. When conditioned media from BrdU-labeled irradiated cells were passed through filters of pore size 0.22 µm and incubated with unexposed cells, BrdU-labeled cfCh particles could be seen to readily enter their nuclei to activate H2AX, active Caspase-3, NFκB, and IL-6. A direct relationship was observed with respect to activation of RIBE biomarkers and radiation dose in the range of 0.1–50 Gy. We confirmed by FISH and cytogenetic analysis that cfCh had stably integrated into chromosomes of bystander cells and had led to extensive chromosomal instability. The above RIBE effects could be abrogated when conditioned media were pre-treated with agents that inactivate cfCh, namely, anti-histone antibody complexed nanoparticles (CNPs), DNase I and a novel DNA degrading agent Resveratrol-copper (R-Cu). Lower hemi-body irradiation with γ-rays (0.1–50 Gy) led to activation of H2AX, active Caspase-3, NFκB, and IL-6 in brain cells in a dose-dependent manner. Activation of these RIBE biomarkers could be abrogated by concurrent treatment with CNPs, DNase I and R-Cu indicating that activation of RIBE was not due to radiation scatter to the brain. RIBE activation was seen even when mini-beam radiation was delivered to the umbilical region of mice wherein radiation scatter to brain was negligible and could be abrogated by cfCh inactivating agents. These results indicate that cfCh released from radiation-induced dying cells are activators of RIBE and that it can be prevented by treatment with appropriate cfCh inactivating agents.