Tumor Budding in Stage II Colon Cancer: Prognostic and Predictive Values
Posted: Tuesday, August 27, 2019
Published in the Journal of Clinical Oncology, a prospective study conducted by Hideki Ueno, MD, PhD, of the National Defense Medical College, Saitama, Japan, and colleagues sought to clarify the prognostic and predictive values of tumor budding in patients with stage II colon cancer who were included in the SACURA trial. This study evaluated the superiority of adjuvant chemotherapy with oral tegafur-uracil over surgery alone. Using the assessment criteria for tumor budding recently defined by the 2016 International Tumor Budding Consensus Conference (ITBCC2016), the investigators concluded that tumour budding grades “should be routinely evaluated in pathologic practice and could improve the benefit of adjuvant chemotherapy for stage II colon cancer.”
The investigators focused on 991 patients with stage II colon cancer between 2006 and 2010. The patients’ tumour budding—“defined as an isolated cancer cell or cluster comprising less than five cells in the invasive front and graded according to its number in a microscopic field with a ×20 objective lens (0.785 mm2) in the hotspot”—was diagnosed based on the ITBCC2016 criteria. Prognostic analyses were conducted 5 years after patient registration.
The results showed that of the 991 tumors, “376, 331, and 284 were classified as BD1 [less than 5 cells in the invasive front], BD2 [five to nine cells in the invasive front], and BD3 [10 or more cells in the invasive front], respectively. The 5-year relapse-free survival rates were 90.9%, 85.1%, and 74.4%, respectively (P < .001) and ranged widely in T4 tumors (86.6% to 53.3%).”
Furthermore, the budding grade was shown to directly correlate with cancer recurrence in the liver, lungs, lymph nodes, and peritoneum, the investigators said. “The prognostic impact of tumor budding has only been evaluated retrospectively, mostly in single-institution cohort studies. In addition, no study has prospectively evaluated the value of the assessment criteria for budding recommended by the ITBCC2016,” they added.
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.