Indicators of cure for women living after uterine and ovarian cancers: a population-based study

This study aims to estimate long-term survival, cancer prevalence, and several cure indicators for Italian women with gynaecological cancers. Thirty-one cancer registries, representing 47% of the Italian female population, were included. Mixture cure models were used to estimate Net Survival (NS), Cure Fraction, Time To Cure (5-year conditional NS>95%), Cure Prevalence (women who will not die of cancer), and Already Cured (living longer than Time to Cure). In 2018, 0.4% (121,704) of Italian women were alive after corpus uteri cancer, 0.2% (52,551) after cervical, and 0.2% (52,153) after ovarian cancer. More than 90% of patients with uterine cancers and 83% with ovarian cancer will not die from their neoplasm (Cure Prevalence). Women with gynaecological cancers have a residual excess risk of death <5% after 5 years since diagnosis. The Cure Fraction was 69% for corpus uteri, 32% for ovarian, and 58% for cervical cancer patients. Time To Cure was ≤10 years for women with gynaecological cancers aged <55 years. 74% of patients with cervical cancer, 63% with corpus uteri cancer, and 55% with ovarian cancer were Already Cured. These results will contribute to improving follow-up programs for women with gynaecological cancers and supporting efforts against discrimination of already cured ones.

Potential for Cure by Stage across the Cancer Spectrum in the United States

BACKGROUND

Cure fraction-the proportion of persons considered cured of cancer after long-term follow-up-reflects the total impact of cancer control strategies, including screening, without lead-time bias. Previous studies have not reported stage-stratified cure fraction across the spectrum of cancer types.

METHODS

Using a mixture cure model, we estimated cure fraction across stages for 21 cancer types and additional subtypes. Cause-specific survival for 2.4 million incident cancers came from 17 US Surveillance, Epidemiology, and End Results registries for adults 40 to 84 years at diagnosis in 2006 to 2015, followed through 2020.

RESULTS

Across cancer types, a substantial cure fraction was evident at early stages, followed by either a sharp drop from stages III to IV or a steady decline from stages I to IV. For example, estimated cure fractions for colorectal cancer at stages I, II, III, and IV were 62% (95% confidence interval: 59%-66%), 61% (58%-65%), 58% (57%-59%), and 7% (7%-7%), respectively. Corresponding estimates for gallbladder cancer were 50% (46%-54%), 24% (22%-27%), 22% (19%-25%), and 2% (2%-3%). Differences in 5-year cause-specific survival between early-stage and stage IV cancers were highly correlated with between-stage differences in cure fraction, indicating that survival gaps by stage are persistent and not due to lead-time bias.

CONCLUSIONS

A considerable fraction of cancer is amenable to cure at early stages, but not after metastasis.

IMPACT

These results emphasize the potential for early detection of numerous cancers, including those with no current screening modalities, to reduce cancer death.

Estimating the cure proportion of stage IA lung adenocarcinoma: a population-based study

BACKGROUND

We aimed to investigate the factors influencing the cure, recurrence, and metastasis rates of stage IA lung adenocarcinoma, using a mixed cure model.

METHODS

A total of 1,064 patients who underwent video-assisted thoracoscopic pulmonectomy were included. Variable screening was performed using the random forest algorithm and least absolute shrinkage and selection operator approaches. The mixed cure model was used to identify factors affecting patient cure and survival, and a sequential analysis was performed on 5%, 10%, and 20% of the presentational subtype concurrently. A receiver operating characteristics curve was used to determine the best model and construct a nomogram to predict the cure rate.

RESULTS

The median follow-up time was 58 (range: 3-115) months. Results from the cure part of the mixed model indicated that the predominant subtype, presentational subtype, and tumor diameter were the main prognostic factors affecting cure rate. Therefore, the nomogram to predict the cure rate was constructed based on these factors. The survival part indicated that the predominant subtype was the only factor that influenced recurrence and metastasis. A sequential analysis of the presentational subtype showed it had no significant effect on survival (P > 0.05). Regardless of the recording mode, no significant improvement was observed in the model's discriminative ability. Only a few postoperative pathological specimens showed lymphovascular invasion (LVI); however, the survival curve suggested a significant effect on patient survival.

CONCLUSIONS

After excluding the existence of long-term survivors, the predominant tumor subtype was determined to be the only factor influencing recurrence and metastasis. Although LVI is rare in stage IA lung adenocarcinoma, its significance cannot be discounted in terms of determining patient prognosis.

A new cure model that corrects for increased risk of non-cancer death: analysis of reliability and robustness, and application to real-life data

BACKGROUND

Non-cancer mortality in cancer patients may be higher than overall mortality in the general population due to a combination of factors, such as long-term adverse effects of treatments, and genetic, environmental or lifestyle-related factors. If so, conventional indicators may underestimate net survival and cure fraction. Our aim was to propose and evaluate a mixture cure survival model that takes into account the increased risk of non-cancer death for cancer patients.

METHODS

We assessed the performance of a corrected mixture cure survival model derived from a conventional mixture cure model to estimate the cure fraction, the survival of uncured patients, and the increased risk of non-cancer death in two settings of net survival estimation, grouped life-table data and individual patients' data. We measured the model's performance in terms of bias, standard deviation of the estimates and coverage rate, using an extensive simulation study. This study included reliability assessments through violation of some of the model's assumptions. We also applied the models to colon cancer data from the FRANCIM network.

RESULTS

When the assumptions were satisfied, the corrected cure model provided unbiased estimates of parameters expressing the increased risk of non-cancer death, the cure fraction, and net survival in uncured patients. No major difference was found when the model was applied to individual or grouped data. The absolute bias was < 1% for all parameters, while coverage ranged from 89 to 97%. When some of the assumptions were violated, parameter estimates appeared more robust when obtained from grouped than from individual data. As expected, the uncorrected cure model performed poorly and underestimated net survival and cure fractions in the simulation study. When applied to colon cancer real-life data, cure fractions estimated using the proposed model were higher than those in the conventional model, e.g. 5% higher in males at age 60 (57% vs. 52%).

CONCLUSIONS

The present analysis supports the use of the corrected mixture cure model, with the inclusion of increased risk of non-cancer death for cancer patients to provide better estimates of indicators based on cancer survival. These are important to public health decision-making; they improve patients' awareness and facilitate their return to normal life.

Measuring population-level cure patterns for cancer patients in the United States

While the life expectancy of cancer survivors has substantially improved over time in the United States, the extent to which cancer patients are cured is not known. Population-level cure patterns are important indicators to quantify cancer survivorships. This population-based cohort study included 8978,721 cancer patients registered in the Surveillance, Epidemiology and End Results (SEER) databases between 1975 and 2018. The primary outcome was cure fractions. Five-year cure probability, time to cure and median survival time of uncured cases were also assessed. All four measures were calculated using flexible parametric models, according to 46 cancer sites, three summary stages, individual age and calendar year at diagnosis. In 2018, cure fractions ranged from 2.7% for distant liver cancer to 100.0% for localized/regional prostate cancer. Localized cancer had the highest cure fraction, followed by regional cancer and distant cancer. Except for localized breast cancer, older patients generally had lower cure fractions. There were 38 cancer site and stage combinations (31.2%) that achieved 95% of cure within 5 years. Median survival time of the uncured cases ranged from 0.3 years for distant liver cancer to 10.9 years for localized urinary bladder cancer. A total of 117 cancer site and stage combinations (93.6%) had increased cure fraction over time. A considerable proportion of cancer patients were cured at the population-level, and the cure patterns varied substantially across cancer site, stage and age at diagnosis. Increases in cure fractions over time likely reflected advances in cancer treatment and early detection.

Cancer Cure and Consequences on Survivorship Care: Position Paper from the Italian Alliance Against Cancer (ACC) Survivorship Care Working Group

A multidisciplinary panel of experts and cancer patients developed a position paper to highlight recent evidence on "cancer cure" (ie, the possibility of achieving the same life expectancy as the general population) and discuss the consequences of this concept on follow-up and rehabilitation strategies. The aim is to inform clinicians, patients, and health-care policy makers about strategies of survivorship care for cured cancer patients and consequences impacting patient lives, spurring public health authorities and research organizations to implement resources to the purpose. Two identifiable, measurable, and reproducible indicators of cancer cure are presented. Cure fraction (CF) is >60% for breast and prostate cancer patients, >50% for colorectal cancer patients, and >70% for patients with melanoma, Hodgkin lymphoma, and cancers of corpus uteri, testis (>90%), and thyroid. CF was >65% for patients diagnosed at ages 15-44 years and 30% for those aged 65-74 years. Time-to-cure was consistently <1 year for thyroid and testicular cancer patients and <10 years for patients with colorectal and cervical cancers, melanoma, and Hodgkin lymphoma. The working group agrees that the evidence allows risk stratification of cancer patients and implementation of personalized care models for timely diagnosis, as well as treatment of possible cancer relapses or related long-term complications, and preventive measures aimed at maintaining health status of cured patients. These aspects should be integrated to produce an appropriate follow-up program and survivorship care plan(s), avoiding stigma and supporting return to work, to a reproductive life, and full rehabilitation. The "right to be forgotten" law, adopted to date only in a few European countries, may contribute to these efforts for cured patients.

Mixture Cure Models in Oncology: A Tutorial and Practical Guidance

Novel cancer therapies are associated with survival patterns that differ from established therapies, which may include survival curves that plateau after a certain follow-up time point. A fraction of the patient population is then considered statistically cured and subject to the same mortality experience as the cancer-free general population. Mixture cure models have been developed to account for this characteristic. As compared to standard survival analysis, mixture cure models can often lead to profoundly different estimates of long-term survival, required for health economic evaluations. This tutorial is designed as a practical introduction to mixture cure models. Step-by-step instructions are provided for the entire implementation workflow, i.e., from gathering and combining data from different sources to fitting models using maximum likelihood estimation and model results interpretation. Two mixture cure models were developed to illustrate (1) an "uninformed" approach where the cure fraction is estimated from trial data and (2) an "informed" approach where the cure fraction is obtained from an external source (e.g., real-world data) used as an input to the model. These models were implemented in the statistical software R, with the freely available code on GitHub. The cure fraction can be estimated as an output from ("uninformed" approach) or used as an input to ("informed" approach) a mixture cure model. Mixture cure models suggest presumed estimates of long-term survival proportions, especially in instances where some fraction of patients is expected to be statistically cured. While this type of model may initially seem complex, it is straightforward to use and interpret. Mixture cure models have the potential to improve the accuracy of survival estimates for treatments associated with statistical cure, and the present tutorial outlines the interpretation and implementation of mixture cure models in R. This type of model will likely become more widely used in health economic analyses as novel cancer therapies enter the market.

Cancer cure for 32 cancer types: results from the EUROCARE-5 study

BACKGROUND

Few studies have estimated the probability of being cured for cancer patients. This study aims to estimate population-based indicators of cancer cure in Europe by type, sex, age and period.

METHODS

7.2 million cancer patients (42 population-based cancer registries in 17 European countries) diagnosed at ages 15-74 years in 1990-2007 with follow-up to 2008 were selected from the EUROCARE-5 dataset. Mixture-cure models were used to estimate: (i) life expectancy of fatal cases (LEF); (ii) cure fraction (CF) as proportion of patients with same death rates as the general population; (iii) time to cure (TTC) as time to reach 5-year conditional relative survival (CRS) >95%.

RESULTS

LEF ranged from 10 years for chronic lymphocytic leukaemia patients to <6 months for those with liver, pancreas, brain, gallbladder and lung cancers. It was 7.7 years for patients with prostate cancer at age 65-74 years and >5 years for women with breast cancer. The CF was 94% for testis, 87% for thyroid cancer in women and 70% in men, 86% for skin melanoma in women and 76% in men, 66% for breast, 63% for prostate and <10% for liver, lung and pancreatic cancers. TTC was <5 years for testis and thyroid cancer patients diagnosed below age 55 years, and <10 years for stomach, colorectal, corpus uteri and melanoma patients of all ages. For breast and prostate cancers, a small excess (CRS < 95%) remained for at least 15 years.

CONCLUSIONS

Estimates from this analysis should help to reduce unneeded medicalization and costs. They represent an opportunity to improve patients' quality of life.

The relative survival and cure fraction of gastric cancer estimated through flexible parametric models using data from population-based cancer registration during 2003-2012 in Linzhou, China

PURPOSE

The proportion of cured gastric cancer patients has drawn the attention of patients, physicians, and healthcare providers after comprehensive prevention and control measures were carried out for several years. Therefore, the relative survival and cure fraction were estimated in our study.

METHODS

Population-based cancer registration data were used to estimate survival and cure fraction. A total of 7585 gastric cancer cases (ICD10:C16.0 ~ C16.9) were extracted and included in the final analysis. Cases were diagnosed in 2003-2012 and followed until the end of 2017. Relative survival was calculated as the ratio between the observed survival through the life-table method. The expected survival was estimated by the Ederer II method. The cure fraction was estimated using flexible parametric cure models stratified by age and calendar period when the cases were diagnosed.

RESULTS

The 5-year relative survival of cardia gastric cancer increased with the calendar period of 2003-2004, 2005-2006, 2007-2008, 2009-2010, and 2011-2012 (27.5%, 28.3%, 33.5%, 38.2%, and 46.8%, respectively). The increasing trend along with the calendar periods was also observed in cure proportion of cardia gastric cancer (24.8%, 25.2%, 31.7%, 36.0%, and 43.1%, respectively). Notable improvement of cure proportion was observed in the period of 2011-2012, compared with the initial period of 2003-2004. There was an improvement of 79.8% among all gastric cancer subjects, and it was 74.1% and 55.7% in cardia gastric and noncardia gastric cancer subjects, respectively. The median survival of "uncured" patients showed no significant improvement along with the calendar periods in all age groups.

CONCLUSIONS

Notable improvement of gastric cancer relative survival and cure proportion was observed in Linzhou during 2003-2012.

Prognosis and cure of long-term cancer survivors: A population-based estimation

BACKGROUND

Increasing evidence of cure for some neoplasms has emerged in recent years. The study aimed to estimate population-based indicators of cancer cure.

METHODS

Information on more than half a million cancer patients aged 15-74 years collected by population-based Italian cancer registries and mixture cure models were used to estimate the life expectancy of fatal tumors (LEFT), proportions of patients with similar death rates of the general population (cure fraction), and time to reach 5-year conditional relative survival (CRS) >90% or 95% (time to cure).

RESULTS

Between 1990 and 2000, the median LEFT increased >1 year for breast (from 8.1 to 9.4 years) and prostate cancers (from 5.2 to 7.4 years). Median LEFT in 1990 was >5 years for testicular cancers (5.8) and Hodgkin lymphoma (6.3) below 45 years of age. In both sexes, it was ≤0.5 years for pancreatic cancers and NHL in 1990 and in 2000. The cure fraction showed a 10% increase between 1990 and 2000. It was 95% for thyroid cancer in women, 94% for testis, 75% for prostate, 67% for breast cancers, and <20% for liver, lung, and pancreatic cancers. Time to 5-year CRS >95% was <10 years for testis, thyroid, colon cancers, and melanoma. For breast and prostate cancers, the 5-year CRS >90% was reached in <10 years but a small excess remained for >15 years.

CONCLUSIONS

The study findings confirmed that several cancer types are curable. Became aware of the possibility of cancer cure has relevant clinical and social impacts.

A cure model survival analysis of patients affected by small intestinal neuroendocrine neoplasms: the Bologna ENETS center experience

PURPOSE

The primary end-point was to evaluate the cure fraction. Secondary end-points were to investigate the time to cure, the excess of death risk, the probability of cure and the factors related to these parameters.

METHODS

Retrospective study of an ENETS database regarding patients affected by Si-NENs. For each patients, clinical, pathological and follow-up data were collected. The survival analysis was made using a novel approach: the cure model approach.

RESULTS

The cure fraction was 92.1%. The death risk, time to cure and the probability of cure were 6/1000 person-years, 3.6 years and 98.2%, respectively. The independent factors influencing these parameters were the grading and the R status (P = 0.041 and P = 0.017, respectively). Patients affected by Si-NENs G2 increased the death risk and time to cure respect to Si-NENs G1 (51 versus 6 per 1000 person-years and 5.1 versus 3.6 years, respectively) as well as patients not operated respect to those radically resected (R0/1) (66 versus 1 per 1000 person-years and 4.8 versus 0.4 years, respectively). The probability of cure decreased (88.1 versus 97.8% and 80.4 versus 99.7%, respectively). R2 resection shows better results than no resection.

CONCLUSIONS

A large portion of patients affected by Si-NENs can be cured. The highest probability of cure regards patients with Si-NENs G1 who underwent to R0/R1 resection; the lower, those with Si-NENs G2 and no resection. R2 resection seems to be preferred respect to no resection.

Time-to-cure and cure proportion in solid cancers in France. A population based study

BACKGROUND

In cancer care, the cure proportion (P) and time-to-cure (TTC) are important indicators for practitioners, patients, and healthcare policy makers. The recent definition of TTC as the time at which the probability of belonging to the cured group reaches 95% was used for the first time.

METHODS

The data stem from the common database of French cancer registries including 335,358 solid tumours diagnosed between 1995 and 2009 at 27 sites. P and TTC were estimated through a flexible parametric net survival cure model for each cancer site, sex, and age at diagnosis with acceptable assumption of cure (excess mortality rate ≤0.05).

RESULTS

TTC was ≤5 years and P was >80% for skin melanoma and thyroid and testis cancers. It was 0 for testis cancer in men <55 and for thyroid cancer in men <45 and women <65. TTC was between 5 and 10 years for all digestive cancers except small intestine and all gynaecologic cancers except breast. It was ≥10 years in prostate, breast, and urinary tract. The range of P according to age and sex was 37-79% for urinary tract 72-88% for prostate and breast, 4-16% for pancreatic and 47-62% for colorectal cancer.

CONCLUSION

Time-to-cure was estimated for the first time from a large national database and individual probabilities of cure. It was 0 in the younger patients with testis or thyroid cancer and <12 years in most cancer sites. These results should help improve access to credit and insurance for patients still alive past the estimated TTCs.

Is radical surgery always curative in pancreatic neuroendocrine tumors? A cure model survival analysis

BACKGROUND

Adjuvant therapy after curative surgery for sporadic pancreatic neuroendocrine tumor (pNETs) is not currently recommended, assuming that all patients could be cured by a radical resection. The aim of our study is to establish how many and which kind of patients remained uncured after radical resection of pNET.

METHODS

Retrospective study involving 143 resected sporadic pNETs. The survival analysis was carried out using the cure model, describing the cure fraction and the excess of risk recurrence. Multivariate analyses were made in order to evaluate the non negligible effect of demographics, clinical and pathological factors on survival parameters. The results were reported as percentages, fractions, ORs and HRs with 95% confidence interval (95 CI %).

RESULTS

The cure fraction and the excess of hazard rate of the whole population were 57.1% (37.4-74.6, 95% CI) and 0.06 (0.03-0.07, 95% CI), respectively. Two independent factors were related to the cure fraction: TNM stage (OR 0.27 ± 0.17; P = 0.002) and grading (OR 0.11 ± 0.18; P = 0.004). Considering the excess of hazard rate, only two independent factors were related to an increased risk of recurrence: TNM stage (HR 3.49 ± 1.12; P = 0.004) and grading (HR 4.93 ± 1.82; P < 0.001).

CONCLUSION

The radical surgery has a high probability of cure in stages I-II or in grading 1 while, in stages III-IV or in grading 3 tumors, surgery alone failed to achieve a "cure". A multimodal treatment should be employed in order to avoid a recurrence of the disease.

XRCC3 Thr241Met and TYMS variable number tandem repeat polymorphisms are associated with time-to-metastasis in colorectal cancer

Background

Metastasis is a major cause of mortality in cancer. Identifying prognostic factors that distinguish patients who will experience metastasis in the short-term and those that will be free of metastasis in the long-term is of particular interest in current medical research. The objective of this study was to examine if select genetic polymorphisms can differentiate colorectal cancer patients based on timing and long-term risk of metastasis.

Methods

The patient cohort consisted of 402 stage I-III colorectal cancer patients with microsatellite instability (MSI)-low (MSI-L) or microsatellite stable (MSS) tumors. We applied multivariable mixture cure model, which is the proper model when there is a substantial group of patients who remain free of metastasis in the long-term, to 26 polymorphisms. Time-dependent receiver operator characteristic (ROC) curve analysis was performed to determine the change in discriminatory accuracy of the models when the significant SNPs were included.

Results

After adjusting for significant baseline characteristics, two polymorphisms were significantly associated with time-to-metastasis: TT and TC genotypes of the XRCC3 Thr241Met (p = 0.042) and the 3R/3R genotype of TYMS 5’-UTR variable number tandem repeat (VNTR) (p = 0.009) were associated with decreased time-to-metastasis. ROC curves showed that the discriminatory accuracy of the model is increased slightly when these polymorphisms were added to the significant baseline characteristics.

Conclusions

Our results indicate XRCC3 Thr241Met and TYMS 5’-UTR VNTR polymorphisms are associated with time-to-metastasis, and may have potential biological roles in expediting the metastatic process. Once replicated, these associations could contribute to the development of precision medicine for colorectal cancer patients.

Defining the Chance of Statistical Cure Among Patients with Extrahepatic Biliary Tract Cancer

BACKGROUND

While surgery offers the best curative-intent treatment, many patients with biliary tract malignancies have poor long-term outcomes. We sought to apply a non-mixture cure model to calculate the cure fraction and the time to cure after surgery of patients with peri-hilar cholangiocarcinoma (PHCC) or gallbladder cancer (GBC).

METHODS

Using the Extrahepatic Biliary Malignancy Consortium, 576 patients who underwent curative-intent surgery for gallbladder carcinoma or peri-hilar cholangiocarcinoma between 1998 and 2014 at 10 major hepatobiliary institutions were identified and included in the analysis. A non-mixture cure model was adopted to compare mortality after surgery to the mortality expected for the general population matched by sex and age.

RESULTS

The median and 5-year overall survival (OS) were 1.9 years (IQR, 0.9-4.9) and 23.9 % (95 % CI, 19.6-28.6). Among all patients with PHCC or GBC, the probability of being cured after surgery was 14.5 % (95 % CI, 8.7-23.2); the time to cure was 9.7 years and the median survival of uncured patients was 1.8 years. Determinants of cure probabilities included lymph node metastasis and CA 19.9 level (p ≤ 0.05). The cure fraction for patients with a CA 19.9 < 50 U/ml and no lymph nodes metastases were 39.0 % versus only 5.1 % among patients with a CA 19.9 ≥ 50 who also had lymph node metastasis.

CONCLUSIONS

Examining an "all comer" cohort, <15 % of patients with PHCC or GBC could be considered cured after surgery. Factors such CA 19.9 level and lymph node metastasis independently predicted long-term outcome. Estimating the odds of statistical cure following surgery for biliary tract cancer can assist in decision-making as well as inform discussions around survivorship.

Neuroendocrine liver metastasis: The chance to be cured after liver surgery

BACKGROUND AND OBJECTIVE

Neuroendocrine liver metastasis tumors (NELM) are a heterogeneous group of neoplasms with varied histologic features and a wide range of clinical behaviors. We aimed to identify the fraction of patients cured after liver surgery for NELM.

METHODS

Cure fraction models were used to analyze 376 patients who underwent hepatectomy with curative intent for NELM.

RESULTS

The median and 5-year disease-free survival (DFS) were 4.5 years and 46%, respectively. The probability of being cured from NELM by liver surgery was 44%; the time to cure was 5.1 years. In a multivariable cure model, type of neuroendocrine tumor (NET), grade of tumor differentiation, and rate of liver involvement resulted as independent predictors of cure. The cure fraction for patients with well differentiated NELM from gastrointestinal NET or a functional pancreatic NET, and with <50% of liver-involvement was 95%. Patients who had moderately/poorly differentiated NELM from a non-functional pancreatic NET, and with <50% of liver-involvement was 43%. In the presence of all the three unfavorable prognostic factors (nonfunctional PNET, liver involvement >50%, moderately/poorly differentiation), the cure fraction was 8%.

CONCLUSIONS

Statistical cure after surgery for NELM is possible, and allow for a more accurate prediction of long-term outcome among patients with NELM undergoing liver resection.

The proportion cured of patients diagnosed with Stage III-IV cutaneous malignant melanoma in Sweden 1990-2007: A population-based study

The survival in cutaneous malignant melanoma (CMM) is highly dependent on the stage of the disease. Stage III-IV CMM patients are at high risk of relapse with a heterogeneous outcome, but not all experience excess mortality due to their disease. This group is referred to as the cure proportion representing the proportion of patients who experience the same mortality rate as the general population. The aim of this study was to estimate the cure proportion of patients diagnosed with Stage III-IV CMM in Sweden. From the population-based Swedish Melanoma Register, we included 856 patients diagnosed with primary Stage III-IV CMM, 1990-2007, followed-up through 2013. We used flexible parametric cure models to estimate cure proportions and median survival times (MSTs) of uncured by sex, age, tumor site, ulceration status (in Stage III patients) and disease stage. The standardized (over sex, age and site) cure proportion was lower in Stage IV CMMs (0.15, 95% CI 0.09-0.22) than non-ulcerated Stage III CMMs (0.48, 95% CI 0.41-0.55) with a statistically significant difference of 0.33 (95% CI = 0.24-0.41). Ulcerated Stage III CMMs had a cure proportion of 0.27 (95% CI 0.21-0.32) with a statistically significant difference compared to non-ulcerated Stage III CMMs (difference 0.21; 95% CI = 0.13-0.30). The standardized MST of uncured was approximately 9-10 months longer for non-ulcerated versus ulcerated Stage III CMMs. We could demonstrate a significantly better outcome in patients diagnosed with non-ulcerated Stage III CMMs compared to ulcerated Stage III CMMs and Stage IV disease after adjusting for age, sex and tumor site.

Can hepatic resection provide a long-term cure for patients with intrahepatic cholangiocarcinoma?

BACKGROUND

A patient can be considered statistically cured from a specific disease when their mortality rate returns to the same level as that of the general population. In the current study, the authors sought to assess the probability of being statistically cured from intrahepatic cholangiocarcinoma (ICC) by hepatic resection.

METHODS

A total of 584 patients who underwent surgery with curative intent for ICC between 1990 and 2013 at 1 of 12 participating institutions were identified. A nonmixture cure model was adopted to compare mortality after hepatic resection with the mortality expected for the general population matched by sex and age.

RESULTS

The median, 1-year, 3-year, and 5-year disease-free survival was 10 months, 44%, 18%, and 11%, respectively; the corresponding overall survival was 27 months, 75%, 37%, and 22%, respectively. The probability of being cured of ICC was 9.7% (95% confidence interval, 6.1%-13.4%). The mortality of patients undergoing surgery for ICC was higher than that of the general population until year 10, at which time patients alive without tumor recurrence can be considered cured with 99% certainty. Multivariate analysis demonstrated that cure probabilities ranged from 25.8% (time to cure, 9.8 years) in patients with a single, well-differentiated ICC measuring ≤5 cm that was without vascular/periductal invasion and lymph nodes metastases versus <0.1% (time to cure, 12.6 years) among patients with all 6 of these risk factors. A model with which to calculate cure fraction and time to cure was developed.

CONCLUSIONS

The cure model indicated that statistical cure was possible in patients undergoing hepatic resection for ICC. The overall probability of cure was approximately 10% and varied based on several tumor-specific factors. Cancer 2015;121:3998-4006. © 2015 American Cancer Society.

The application of cure models in the presence of competing risks: a tool for improved risk communication in population-based cancer patient survival

Quantifying cancer patient survival from the perspective of cure is clinically relevant. However, most cure models estimate cure assuming no competing causes of death. We use a relative survival framework to demonstrate how flexible parametric cure models can be used in combination with competing-risks theory to incorporate noncancer deaths. Under a model that incorporates statistical cure, we present the probabilities that cancer patients (1) have died from their cancer, (2) have died from other causes, (3) will eventually die from their cancer, or (4) will eventually die from other causes, all as a function of time since diagnosis. We further demonstrate how conditional probabilities can be used to update the prognosis among survivors (eg, at 1 or 5 years after diagnosis) by summarizing the proportion of patients who will not die from their cancer. The proposed method is applied to Swedish population-based data for persons diagnosed with melanoma, colon cancer, or acute myeloid leukemia between 1973 and 2007.

Long-term survival, prevalence, and cure of cancer: a population-based estimation for 818 902 Italian patients and 26 cancer types

Original, population-based estimates of indicators of long-term survival and cure in cancer patients are provided. More than a quarter of cancer patients in Italy have reached death rates similar to those of the general population. Nearly three quarters of them will not die as a result of cancer. These estimates are potentially helpful to health-care planners, clinicians, and patients.

Background

Persons living after a cancer diagnosis represent 4% of the whole population in high-income countries. The aim of the study was to provide estimates of indicators of long-term survival and cure for 26 cancer types, presently lacking.

Patients and methods

Data on 818 902 Italian cancer patients diagnosed at age 15–74 years in 1985–2005 were included. Proportions of patients with the same death rates of the general population (cure fractions) and those of prevalent patients who were not at risk of dying as a result of cancer (cure prevalence) were calculated, using validated mixture cure models, by cancer type, sex, and age group. We also estimated complete prevalence, conditional relative survival (CRS), time to reach 5- and 10-year CRS >95%, and proportion of patients living longer than those thresholds.

Results

The cure fractions ranged from >90% for patients aged <45 years with thyroid and testis cancers to <10% for liver and pancreatic cancers of all ages. Five- or 10-year CRS >95% were both reached in <10 years by patients with cancers of the stomach, colon–rectum, pancreas, corpus and cervix uteri, brain, and Hodgkin lymphoma. For breast cancer patients, 5- and 10-year CRSs reached >95% after 19 and 25 years, respectively, and in 15 and 18 years for prostate cancer patients. Five-year CRS remained <95% for >25 years after cancer diagnosis in patients with liver and larynx cancers, non-Hodgkin lymphoma, myeloma, and leukaemia. Overall, the cure prevalence was 67% for men and 77% for women. Therefore, 21% of male and 31% of female patients had already reached 5-year CRS >95%, whereas 18% and 25% had reached 10-year CRS >95%.

Conclusions

A quarter of Italian cancer patients can be considered cured. This observation has a high potential impact on health planning, clinical practice, and patients' perspective.

Site-specific proportion cured models applied to cancer registry data

PURPOSE

Proportion-cured models were applied to evaluate their applicability on data from a relatively small cancer registry and to assess the up-to-date survival level of major cancer types in Tyrol, Austria.

METHODS

In total, the 25 most common types of cancer were analyzed with mixture cure models using the period approach for estimation of the proportion cured and median survival time of the fatal cases.

RESULTS

For several of the cancer types, no estimates could be obtained. The models converged for 14 sites among females and for 15 among males. The highest estimate of the proportion cured was found for cervix cancer (74.0 %; 95 % CI 64.4-83.6) and the lowest for male pancreas cancer (4.6 %; 95 % CI 0.2-9.0). The highest median survival of the uncured was 2.7 years (95 % CI 1.2-6.0) for male larynx cancer and the lowest 0.3 years (95 % CI 0.1-0.6) for male acute myeloblastic leukemia (AML).

CONCLUSIONS

The estimates seem reliable for stomach, colon, rectum, pancreas, lung, cervix, ovary, central nervous system/brain and AML cancer and among men also for head/neck, esophagus, liver and kidney cancer. Altogether, it is demonstrated that even data from a regional cancer registry covering a rather small region can be utilized to derive up-to-date survival estimates of various cancer types, enabling monitoring of the development and changes in cancer treatment. Moreover, potentially this methodology is advantageously employable in any situation where the number of cancer cases is limited.

Estimating the cure proportion of malignant melanoma, an alternative approach to assess long term survival: a population-based study

OBJECTIVES

A large proportion of patients with cutaneous malignant melanoma (CMM) do not experience excess mortality due to their disease. This group of patients is referred to as the cure proportion. Few studies have examined the possibility of cure for CMM. The aim of this study was to estimate the cure proportion of patients with CMM in a Swedish population.

METHODS

We undertook a population-based study of 5850 CMM patients in two Swedish health care regions during 1996-2005. We used flexible parametric cure models to estimate cure proportions and median survival times (MSTs) of uncured by stage, sex, age and anatomical site.

RESULTS

Disease stage at diagnosis was the most important factor for the probability of cure, with a cure proportion of approximately 1.0 for stage IA. While the probability of cure decreased with older age, the influence of age was smaller on the MST of uncured. Differences in prognosis between males and females were mainly attributed to differences in cure as opposed to differences in MST of uncured.

CONCLUSIONS

This population-based study showed approximately 100% cure among stage IA disease. Almost 50% of patients had stage IA disease and the high cure proportion for this large patient group is reassuring.