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. 2024 Jan-Dec:31:10732748241285480.
doi: 10.1177/10732748241285480.

Survival Dynamics in Advanced Ovarian Cancer: R2 Resection Versus No-Surgery Paths Explored

Konstantinos Pitsikakis  1 , Diederick DeJong  1 , Konstantinos Kitsos-Kalyvianakis  1 , Marios Evangelos Mamalis  2 , Michela Quaranta  1 , Aishath Shavee  3 , Alina Wahab  3 , Amudha Thangavelu  1 , Timothy Broadhead  1 , David Nugent  1 , Evangelos Kalampokis  2 , Alexandros Laios  1
Affiliations

Survival Dynamics in Advanced Ovarian Cancer: R2 Resection Versus No-Surgery Paths Explored

Konstantinos Pitsikakis et al. Cancer Control. 2024 Jan-Dec.

Abstract

Background: Cytoreductive surgery is critical for optimal tumor clearance in advanced epithelial ovarian cancer (EOC). Despite best efforts, some patients may experience R2 (>1 cm) resection, while others may not undergo surgery at all. We aimed to compare outcomes between advanced EOC patients undergoing R2 resection and those who had no surgery.

Methods: Retrospective data from 51 patients with R2 resection were compared to 122 patients with no surgery between January 2015 and December 2019 at a UK tertiary referral centre. Progression-free survival (PFS) and overall survival (OS) were the study endpoints. Principal Component Analysis and Term Frequency - Inverse Document Frequency scores were utilized for data discrimination and prediction of R>2 cm from computed tomography pre-operative reports, respectively.

Results: No statistical significance was observed, except for age (73 vs 67 years in the no- surgery vs R2 group, P: .001). Principal Components explained 34% of data variances. Reasons for no surgery included age, co-morbidities, patient preference, refractory disease, patient deterioration or disease progression, and absence of measurable intra- abdominal disease). The median PFS and OS were 12 and 14 months for no-surgery, vs 14 and 26 months for R2 (P: .138 and P: .001, respectively). Serous histology and performance status independently predicted PFS in both no-surgery and R2 cohorts. In the no-surgery cohort, serous histology independently predicted OS, while in the R2 cohorts, both serous histology and adjuvant chemotherapy were independent prognostic features for OS. The bi-grams "abdominopelvic ascites" and "solid omental" were amongst those best discriminating between R>2 cm and R1-2 cm.

Conclusions: R2 resection and no-surgery cohorts displayed unfavourable prognosis with a notable degree of uniformity. When cytoreduction results in suboptimal results, the survival benefit may still be higher compared to those who underwent no surgery.

Keywords: R2 resection; cytoreduction; epithelial ovarian cancer; machine learning; natural language processing; principal component analysis; prognosis estimation; survival analysis.

Plain language summary

The study examined outcomes in advanced epithelial ovarian cancer (EOC) patients who underwent either R2 (suboptimal) surgical resection or received no surgery at all at a UK tertiary referral center. Sophisticated machine learning methodolgies were used to analyze data patterns and predict the extent of resection (>2 cm) from pre-operative CT reports. Reasons for not undergoing surgery included older age, presence of other medical conditions, patient preference, progressive disease, patient decline, or lack of detectable intra-abdominal disease. Factors like serous histology and performance status iinfluenced the risk of recurrence in both groups, while serous histology and adjuvant chemotherapy predicted the risk of death in the R2 group. Word sequences like “omental disease” and “reduced bulk” helped differentiate between R>2 cm and less extensive resections (R1-2 cm). In summary, both R2 resection and no-surgery groups had poor outcomes, but patients who underwent R2 resection generally had better survival compared to those who received no surgery, even when complete tumor removal was not achieved.

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Conflict of interest statement

Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Figures

Figure 1.
Figure 1.
Principal Component Analysis plot on the four variables commonly shared between the R2 resection and non-surgery groups. The first two principal components accounted for 34% of the data variance.
Figure 2.
Figure 2.
Cohort survival outcomes. Kaplan-Meier curves demonstrating: (A) progression-free-survival (B) overall-survival (blue = R2 resection; orange = non-surgery) analysed by the two groups (blue = R2 resection; orange = non-surgery).
Figure 3.
Figure 3.
Hazard ratio and 95% confidence intervals for univariate Cox regression analysis: (A) recurrence and non-recurrence in the non-surgery group (B) recurrence and non-recurrence in the R2 resection group (C) fatal and non-fatal outcomes in the non-surgery group (D) fatal and non-fatal outcomes in the R2 resection group.
Figure 4.
Figure 4.
Hazard ratio (HR) and 95% confidence intervals (CIs) for prospective log-linear associations (Cox regression) from multivariate analysis: (A) recurrence and non-recurrence in the non-surgery group (B) recurrence and non-recurrence in the R2 resection group (C) fatal and non-fatal outcomes in the non-surgery group (D) fatal and non-fatal outcomes in the R2 resection group.
Figure 5.
Figure 5.
Survival outcomes in the non-surgery group. Kaplan-Meier curves demonstrating: (A) progression-free-survival (B) overall-survival for patients without evidence of intrabdominal disease (herein referred as G6, blue), and those who underwent no surgery for other reasons (Non-G6, orange).
Figure 6.
Figure 6.
2-gram word clouds from CT reports best discriminating R >2 cm resection (left) and R1-2 cm resection (right).
See this image and copyright information in PMC

References

    1. Siegel RL, Miller KD, Wagle NS, Jemal A. Cancer statistics, 2023. CA Cancer J Clin. 2023;73(1):17-48. doi:10.3322/caac.21763 - DOI - PubMed
    1. Griffiths CT. Surgical resection of tumor bulk in the primary treatment of ovarian carcinoma1 c. thomas griffiths 2 summary-the effect of tumor bulk resection on survival was studied in 102 patients with stages ii and iii ovarian cancer. a multiple linear regression equation provided both simultane. In: Symposium on Ovarian Carcinoma, November 15 and 16, 1974, Reston, Virginia. US Department of Health and Human Services, Education, and Welfare, Public, p. 101.
    1. Laios A, Katsenou A, Tan YS, et al. Feature selection is critical for 2-year prognosis in advanced stage high grade serous ovarian cancer by using machine learning. Cancer Control. 2021;28:10732748211044678. doi:10.1177/10732748211044678 - DOI - PMC - PubMed
    1. Fernandes MC, Nikolovski I, Long Roche K, Lakhman Y. Ct of ovarian cancer for primary treatment planning: what the surgeon needs to know—radiology in training. Radiology. 2022;304(3):516-526. doi:10.1148/radiol.212737 - DOI - PMC - PubMed
    1. Schwartz LH, Panicek DM, Berk AR, Li Y, Hricak H. Improving communication of diagnostic radiology findings through structured reporting. Radiology. 2011;260(1):174-181. doi:10.1148/radiol.11101913 - DOI - PMC - PubMed

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