Adjuvant Therapy Reduces Rate of Dissemination but Shortens Survival Thereafter

Systemic Administration of Cowpea Mosaic Virus Demonstrates Broad Protection Against Metastatic Cancers

The key challenge in cancer treatment is prevention of metastatic disease which is therapeutically resistant and carries poor prognoses necessitating efficacious prophylactic approaches that prevent metastasis and recurrence. It is previously demonstrated that cowpea mosaic virus (CPMV) induces durable antitumor responses when used in situ, i.e., intratumoral injection. As a new direction, it is showed that CPMV demonstrates widespread effectiveness as an immunoprophylactic agent - potent efficacy is demonstrated in four metastatic models of colon, ovarian, melanoma, and breast cancer. Systemic administration of CPMV stimulates the innate immune system, enabling attack of cancer cells; processing of the cancer cells and associated antigens leads to systemic, durable, and adaptive antitumor immunity. Overall, CPMV demonstrated broad efficacy as an immunoprophylactic agent in the rejection of metastatic cancer.

Invasive breast cancer over four decades reveals persisting poor metastatic outcomes in treatment resistant subgroup - the "ATRESS" phenomenon

BACKGROUND

Major advances in breast cancer treatment have led to a reducuction in mortality. However, there are still women who are not cured. We hypothesize there is a sub-group of women with treatment-resistant cancers causing early death.

METHODS

Between 1975 and 2006, 5392 women with invasive breast cancer underwent surgery at Guy's Hospital, London. Data on patient demographics, tumour characteristics, treatment regimens, local recurrence, secondary metastasis, and death were prospectively recorded. We considered four time periods (1975-1982, 1983-1990, 1991-1998, 1999-2006). Risks and time to event analysis were performed with Cox proportional hazards model and Kaplan-Meier estimation.

RESULTS

Unadjusted hazard ratios for developing metastasis and overall mortality relative to the 1975-1982 cohort decreased steadily to 0.23 and 0.63, respectively in 1999-2006. However, metastasis-free interval shortened, with the proportion of women developing metastasis ≤5 years increasing from 73.9% to 83.0%. Furthermore, median post-metastatic survival decreased from 1.49 years to 0.94 years. Applying our risk criteria identified the presence of ±200 patients in each cohort who developed metastasis early and died within a much shorter time frame.

CONCLUSIONS

Advances in treatment have decreased the risk of metastasis and improved survival in women with invasive breast cancer over the last 40 years. Despite this, a subpopulation with shorter metastasis-free and post-metastatic survival who are unresponsive to available treatment remains. This may be due to the ATRESS phenomenon (adjuvant therapy-related shortening of survival) secondary to preselection inherent in adjuvant therapy, successful treatment of less malignant tumour cells and treatment-induced resistance in the remaining tumour clones.