neoadjuvant or adjuvant chemotherapy

Overview

Neoadjuvant or adjuvant chemotherapy refers to systemic anticancer drug treatment given either before definitive local therapy (neoadjuvant chemotherapy) or after surgery or other primary treatment (adjuvant chemotherapy). In oncology, these approaches are used to reduce tumor burden, improve resectability, eradicate micrometastatic disease, and improve long-term disease control. Their use is highly disease-specific and depends on tumor biology, stage, patient fitness, and the planned local treatment strategy.

Biologically, neoadjuvant chemotherapy can also serve as an in vivo test of treatment sensitivity, allowing assessment of pathologic response such as complete pathologic response. Adjuvant chemotherapy is intended to eliminate residual microscopic disease after resection. Recent studies have examined these strategies across breast cancer, pancreatic cancer, gastric cancer, colorectal cancer, rectal cancer, sarcoma, bladder cancer, osteosarcoma, and male breast cancer, often in combination with agents such as pembrolizumab, durvalumab, serplulimab, oxaliplatin, fluorouracil, capecitabine, cyclophosphamide, and cisplatin. Related research has also explored interactions with immune microenvironments, including tertiary lymphoid structures, B-cell populations, and CD8+ S100B+ T cells, as well as resistance mechanisms involving cancer-associated fibroblast biology and oxidative stress pathways.

Recent Publications Summary

Recent publications on neoadjuvant or adjuvant chemotherapy have focused on its role in solid tumors, particularly in refining patient selection, estimating benefit, and understanding treatment completion. In gallbladder cancer, a machine learning-based early recurrence model was used to stratify patients after surgery and guide adjuvant chemotherapy decisions; among 395 patients, adjuvant chemotherapy was associated with a significantly higher 5-year overall survival in the high-risk group, but not in the low-risk group 42325014Jun. In non-metastatic sarcoma, adjuvant chemotherapy was evaluated through a cost-effectiveness analysis based on real-world data from the French nationwide DEEPSARC study, reflecting ongoing debate about its survival value 42334926Jun. In pancreatic cancer after pancreaticoduodenectomy, investigators examined preoperative serum total cholesterol as a predictor of adjuvant chemotherapy completion, emphasizing that completion of postoperative treatment is an important determinant of long-term outcome 42203346May.

Neoadjuvant chemotherapy was also studied as a prognostic and response-modifying strategy. In male breast cancer, a retrospective SEER-based cohort analysis assessed neoadjuvant chemotherapy alone and in combination with adjuvant chemotherapy, reporting that pathological complete response was uncommon but associated with improved overall survival and breast cancer-specific survival compared with non-pCR patients 42204769May. In osteosarcoma, machine learning with clinical data and T2-weighted MRI radiomics was used to predict resistance to neoadjuvant chemotherapy, with histological response serving as the reference standard and external validation included 42159937May. For high-risk locally advanced rectal cancer, a propensity score matched study directly compared total neoadjuvant therapy with neoadjuvant chemotherapy alone, reflecting uncertainty about the added value of radiotherapy-containing approaches in some populations 42171940May.

Across these studies, neoadjuvant or adjuvant chemotherapy was mainly examined in the context of real-world treatment optimization rather than as a uniform intervention. The publications collectively highlight efforts to identify subgroups most likely to benefit from adjuvant chemotherapy, to predict recurrence or resistance before treatment, and to understand factors influencing whether patients can complete planned postoperative therapy 42325014Jun42203346May42159937May.

What Changes, What Holds

1. Adjuvant benefit now looks risk-stratified rather than routine
NEW DIRECTION Recent work suggests postoperative chemotherapy should be selected more selectively in gallbladder cancer, with benefit concentrated in patients identified as high risk for recurrence rather than applied uniformly. That does not overturn the established adjuvant role, but it narrows how that role should be operationalized: the key question becomes which patients are likely to gain enough to justify treatment. The pancreatic cancer analysis also reinforces that completing planned postoperative therapy matters, making tolerability and delivery part of the decision framework 42325014Jun42203346May.

2. Response prediction is becoming more central than treatment assignment alone
METHOD These studies mainly change how neoadjuvant or adjuvant chemotherapy is evaluated: machine learning, radiomics, and propensity matching are being used to predict resistance, interpret response, and compare treatment strategies more precisely. The established account of neoadjuvant chemotherapy as a way to reduce tumor burden and test sensitivity still stands, but the new work shifts emphasis toward pre-treatment prediction and post-treatment prognostication. The male breast cancer cohort also reinforces that pathologic complete response remains a meaningful response marker when it occurs 42159937May42204769May42171940May.

3. The main unresolved issue is not whether chemotherapy can help, but who can complete and benefit from it
REINFORCES This paragraph sharpens the baseline’s disease-specific caution by showing that real-world utility depends on patient selection, recurrence risk, and treatment completion. It does not add a new biological role for neoadjuvant or adjuvant chemotherapy, but it reinforces that these approaches are conditional tools rather than universal standards. The sarcoma cost-effectiveness work and the pancreatic completion predictor both point to the same practical uncertainty: survival value remains debated unless patients can actually receive the intended postoperative course 42334926Jun42203346May.

Overview update candidates: risk-stratified adjuvant use in gallbladder cancer; treatment completion as a determinant of postoperative benefit; stronger emphasis on predictive modeling for neoadjuvant resistance and response.