Conditional Relative Survival of Ovarian Cancer: A Korean National Cancer Registry Study

Abstract

ObjectiveConditional relative survival (CRS) rates, which take into account changes in prognosis over time, are useful estimates for survivors and their clinicians as they make medical and personal decisions. We aimed to present the 5-year relative conditional survival probabilities of patients diagnosed with ovarian cancer from 1997–2016.MethodsThis nationwide retrospective cohort study used data from the Korean Central Cancer Registry. Patients diagnosed with ovarian cancer between 1997 and 2016 were included. CRS rates were calculated stratified by age at diagnosis, cancer stage, histology, treatment received, year of diagnosis, and social deprivation index.ResultsThe 5-year relative survival rate at the time of diagnosis was 61.1% for all cases. The probability of surviving an additional 5 years, conditioned on having already survived 1, 2, 3, 4, and 5 years after diagnosis was 65.0, 69.5, 74.6, 79.3, and 83.9%, respectively. Patients with poorer initial survival estimates (older, distant stage, serous histology) generally showed the largest increases in CRS over time. The probability of death was highest in the first year after diagnosis (11.8%), and the conditional probability of death in the 2nd, 3rd, 4th, and 5th years declined to 9.4%, 7.9%, 6.1%, and 5.2%, respectively.ConclusionCRS rates for patients with ovarian cancer increased with each year they survived, but this did not reach the level of ‘no excess mortality’ even 5 years after diagnosis. The largest improvements in CRS were observed in patients with poorer initial prognoses. Our findings provide updated prognosis to ovarian cancer survivors and clinicians.

Projection of Cancer Incidence and Mortality From 2020 to 2035 in the Korean Population Aged 20 Years and Older

“…For ovarian cancer, the ASMR was predicted to be approximately 1.4 times higher in 2035 than in 2000. Effective screening modalities or nationwide screening programs are needed to reduce the mortality rate of ovarian cancer, since ovarian cancer has the poorest survival rate because it is asymptomatic in the early stages and usually detected at an advanced stage [ 22 ].…”

Stratifying the risk of ovarian cancer incidence by histologic subtypes in the Korean Epithelial Ovarian Cancer Study (Ko‐EVE)

“… 9 However, the origin of MUC, accounting for 16.2% of the total EOC incidence in Korea, has not been well established. 9 These subtypes are heterogeneous in their clinical course, with the worst clinical course seen in the HGS subtype. 10 Moreover, the four subtypes have different molecular alterations and gene expression, and different carcinogenic mechanisms across the subtypes have been proposed based on their genetic and molecular backgrounds.…”

“…The origin of LGS is associated with stepwise progression from benign through borderline tumor to noninvasive and invasive 8 . Serous carcinoma accounts for nearly 48% of cases in Korea and most prevalent serous carcinoma is HGS 9 . END and CLC originate from endometriotic lesions, and each account for nearly 9% of the total EOC incidence in Korea 9 .…”

“…Serous carcinoma accounts for nearly 48% of cases in Korea and most prevalent serous carcinoma is HGS 9 . END and CLC originate from endometriotic lesions, and each account for nearly 9% of the total EOC incidence in Korea 9 . However, the origin of MUC, accounting for 16.2% of the total EOC incidence in Korea, has not been well established 9 .…”

Trends in the Incidence and Survival Rates of Primary Ovarian Clear Cell Carcinoma Compared to Ovarian Serous Carcinoma in Korea

“…To date, only few studies have reported nationwide survival outcomes of primary OCCC in Korea ( 3 , 16 ). However, none of these studies directly compared the baseline characteristics and survival of OCCC with those of other histologic subtypes.…”