Researchers at the Johns Hopkins Kimmel Cancer Center and the Bloomberg~Kimmel Institute for Cancer Immunotherapy have released updated consensus guidelines, along with a reproducibility study, to standardize how pathologists evaluate tumor response to neoadjuvant therapy across a wide range of solid tumors.
Supported by the National Institutes of Health (NIH) and The Mark Foundation for Cancer Research, and developed in collaboration with the Society for Immunotherapy of Cancer (SITC) and the International Neoadjuvant Melanoma Consortium (INMC), these multi-institutional guidelines were published on November 4, 2025, in the Annals of Oncology [1]. They represent the first unified, pan-tumor framework for assessing the percentage of residual viable tumor (RVT)*, the percentage of necrosis, and the percentage of regression (histologic signs of inflammation and tissue repair) after presurgical treatment.
Refine and broaden
The recommendations refine and broaden earlier immune-based scoring criteria first introduced in lung cancer in 2018 and later expanded in 2020. Now updated with five years of clinical experience and new reproducibility data, these guidelines offer a standardized approach informed by field feedback and the latest research findings.
A related study, published February 2, 2026 edition of Annals of Oncology, demonstrated that the guidelines produce consistent results across multiple tumor types, even when applied by different pathologists worldwide.[2]
“Neoadjuvant therapy is being used in more cancer types, and pathologic response is becoming an important predictor of long-term survival and a key endpoint in clinical trials,” said lead author Julie Stein Deutsch, M.D., assistant professor of dermatology, pathology, and oncology.
Complicated comparison
“However, previous scoring systems have differed by tumor type, complicating study comparisons and clinical practice. Our unified guidelines provide a common language to improve clinical care, research, and regulatory processes,” Deutsch explained.
The updated framework was motivated by growing evidence that tissue changes signaling a treatment response—especially after immunotherapy—are remarkably similar across many cancer types. The research team had previously reviewed roughly 500 specimens treated with anti-PD-1 immunotherapy alone or with agents like chemotherapy, and found consistent response patterns regardless of tumor origin.
Collaborating with SITC and INMC, Johns Hopkins investigators developed this harmonized system to avoid confusion and improve comparability across studies.
“Most pathologists are generalists, not focused on a single tumor type,” noted senior author Janis Taube, M.D., director of dermatopathology and co-director of the Bloomberg~Kimmel Institute tumor microenvironment laboratory.
Key advantage
“Switching between multiple scoring systems is inefficient and can result in inconsistent reports. Our findings show that a unified, pan-tumor system is both effective and reliable—no tumor-specific system outperforms it in predicting patient outcomes,” Taube added.
A key advancement of the new guidelines is their proven reproducibility. In a large, multi-institutional study involving 14 pathologists, the updated RVT scoring method yielded highly consistent results after a brief, standardized training.[2]
Pathologists achieved strong agreement in assessing RVT, regression, and necrosis, regardless of tumor type, specimen location, or whether the sample was a biopsy or surgical resection. These results, presented at the 2024 American Society of Clinical Oncology annual meeting, support the adoption of a unified system akin to RECIST, the standard for measuring tumor changes on imaging scans. The guidelines lay the groundwork for standardized data collection as neoadjuvant and perioperative therapies continue to expand across cancer types.
“Reproducibility is critical,” emphasized Deutsch.
“For these metrics to guide care and clinical trials, different pathologists must produce similar results. Our new training materials make this achievable, and we are collaborating with SITC to share these resources widely.”
The team’s next steps include refining clinically relevant RVT thresholds for individual cancer types as more survival data become available.
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Note: * Residual viable tumor (RVT) refers to cancer cells that remain in the body after treatment, such as chemotherapy, immunotherapy, or surgery. It is a critical pathological marker for predicting long-term survival and treatment response, especially in lung cancer, where a low percentage often indicates a major pathologic response and better prognosis.
Reference
[1] Deutsch JS, Scolyer RA, Burton E, Busam KJ, Chen KY, Cimino-Mathews A, Cottrell TR, de Andrea CE, Fiset PO, Long GV, Messina J, Rawson RV, Salgado R, Schürch CM, Seethala RR, Sholl LM, Signoretti S, Topalian SL, van de Wiel BA, Xu X, Gershenwald JE, Tetzlaff MT, Taube JM. Updated pan-tumor guidelines for neoadjuvant scoring of pathologic response: a joint SITC and INMC effort. Ann Oncol. 2026 Feb;37(2):141-154. doi: 10.1016/j.annonc.2025.10.018. Epub 2025 Nov 4. PMID: 41469296.
[2] Deutsch JS, Cottrell TR, Chen KY, De Andrea CE, Baraban E, Fiset PO, Jedrych JJ, Orr CE, Real F, Salgado R, Schürch CM, Scolyer RA, Seethala R, Sholl LM, Signoretti S, Tetzlaff M, Wang H, Wang T, Weissferdt A, Xu X, Ziai J, Cimino-Mathews A, Taube JM. Pan-tumor harmonization of pathologic response assessment for standardized data collection in neoadjuvant trials (PATHdata): Results of a Society for Immunotherapy of Cancer multi-institutional reproducibility study. Ann Oncol. 2026 Feb 2:S0923-7534(26)00038-4. doi: 10.1016/j.annonc.2026.01.011. Epub ahead of print. PMID: 41638487.
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