SAN DIEGO – Among patients with stage IB cervical cancer, deep stromal invasion and large tumor size are the two biggest factors associated with increased risk of recurrence. Higher risk-weighted surgical-pathological scores were also associated with decreased benefit of concurrent chemoradiotherapy after surgery.
Those are key findings from a Gynecologic Oncology Group (GOG) ancillary data analysis reported by Dr. Koji Matsuo at the annual meeting of the Society of Gynecologic Oncology.
“Surgery remains the mainstay of treatment for early-stage cervical cancer,” Dr. Matsuo, assistant director of the gynecologic oncology clinic at the University of Southern California, Los Angeles, said in an interview prior to the meeting. “Surgical specimen is useful to identify certain types of factors that can benefit from postoperative adjuvant therapy with concurrent chemoradiotherapy. Traditionally, tumor factors are grouped into high, intermediate, and low risk. Tumors often exhibit multiple risk factors and magnitude of significance for survival may differ across the tumor factors. In this study, we examined the effects of combination of multiple risk factors by weighing magnitude of significance for recurrence.”
The researchers analyzed data from 1,538 stage IB cervical cancer patients who underwent primary radical hysterectomy and pelvic lymphadenectomy. They used a multivariate model to examine hazard ratios associated with disease-free survival (DFS) for seven surgical-pathological risk factors: nodal metastasis, parametrial involvement, surgical margin, lymphovascular space invasion (LVSI), deep stromal invasion, large tumor, and histology. Next, they used a risk-weighted surgical-pathological score (a sum of HR scores) to determine DFS and compared it to a traditional risk factor model.
The median age of patients in the study was 41 years, the median follow-up time was 84 months, the recurrence rate was 26%, and the mortality rate was 27%.
Dr. Matsuo reported that based on the risk-weighted surgical-pathological score model, factors associated with the highest risk of recurrence were deep stromal invasion (HR 1.85), large tumor size (HR 1.81), parametrial involvement (HR 1.73), LVSI (HR 1.37), histology (HR 1.30), and nodal metastasis (HR 1.29; P less than .05 for all).
The 5-year DFS rates based on risk-weighted scores were 85.6% for score 0, 89.1% for the first quartile, 79.6% for the second quartile, 69.3% for the third quartile, and 50.2% for fourth quartile (P less than .001). A fourth-quartile score in the risk-weighted model had a significantly lower 5-year DFS rate, compared with the traditional risk factor model high-risk group (50.2% vs. 60.9%; P less than .001).
Dr. Matsuo and his associates also found that higher risk-weighted surgical-pathological scores were associated with decreased benefit of concurrent chemoradiotherapy after surgery.
“That has been the mainstay of postoperative treatment in adjuvant therapy for a group of cervical cancer with high risk of recurrence,” he said. “It is beneficial to be aware that each tumor factor has a different risk for recurrence and tumors may exhibit multiple risk factors that can be associated with decreased benefit of concurrent chemoradiotherapy after surgical treatment.”
He acknowledged certain limitations of the study, including the lack of information regarding the site of recurrence.
Dr. Matsuo reported having no financial disclosures.