The rare cancer network: ongoing studies and future strategy

The interaction of rurality and rare cancers for travel time to cancer care

PURPOSE

Geographic access to cancer care is known to significantly impact utilization and outcomes. Longer travel times have negative impacts for patients requiring highly specialized care, such as for rare cancers, and for those in rural areas. Scant population-based research informs geographic access to care for rare cancers and whether rurality impacts that access.

METHODS

Using Medicare data (2014-2015), we identified prevalent cancers and cancer-directed surgeries, chemotherapy, and radiation. We classified cancers as rare (incidence <6/100,000/year) or common (incidence ≥6/100,000/year) using previously published thresholds and categorized rurality from ZIP code of beneficiary residence. We estimated travel time between beneficiaries and providers for each service based on ZIP code. Descriptive statistics summarized travel time by rare versus common cancers, service type, and rurality.

FINDINGS

We included 1,169,761 Medicare beneficiaries (21.9% in nonmetropolitan areas), 87,399; 7.5% had rare cancers, with 9,133,003 cancer-directed services. Travel times for cancer services ranged from approximately 29 minutes (25th percentile) to 68 minutes (75th percentile). Travel times were similar for rare and common cancers overall (median: 45 vs 43 minutes) but differed by service type; 13.4% of surgeries were >2 hours away for rare cancers, compared to 8.3% for common cancers. Increasing rurality disproportionately increased travel time to surgical care for rare compared to common cancers.

CONCLUSIONS

Travel times to cancer services are longest for surgery, especially among rural residents, yet not markedly longer overall between rare versus common cancers. Understanding geographic access to cancer care for patients with rare cancers is important to delivering specialized care.

Impact of radiotherapy on survival in resected or unresectable anaplastic thyroid carcinomas, a Rare Cancer Network study

PURPOSE

Anaplastic thyroid carcinomas (ATC) are a heterogenous group of tumors of overall dismal prognosis. We designed models to identify relevant prognostic factors of survival of irradiated ATC patients including radiotherapy modalities (field size, dose).

MATERIAL AND METHODS

Between 2000 and 2017, 166 ATC patients' treatments were divided into surgery and postoperative radiotherapy (poRT) or definitive radiotherapy (RT). Multiple imputation approach was used for missing data. Prognostic factors were identified using Lasso-penalized Cox modelling and predicted risk scores were built.

RESULTS

Patients undergoing RT (n=70) had more adverse patient and disease characteristics than those undergoing poRT (n=96). Corresponding median survival rates were 5.4 and 12.1 months, respectively. PoRT patients undergoing poRT more likely received extended-field radiotherapy with prophylactic nodal irradiation, but rather received platinum- vs. adriamycin-based chemoradiotherapy. Radiotherapy was conventionally fractionated, delivered >60Gy in 51.9% and 61.7% and used extended fields in 88.5% and 71.2% of patients with poRT or RT. Radiotherapy interruption rates for toxicity were similar in the two groups. The best poRT-group model identified age>45yo, PS≥1, pathologic tumor stage≥pT4b,>N1 and R2 resection as poor prognostic factors. The best RT-group model (C-index of 0.72) identified PS≥3,>N1 and extended-field radiotherapy with prophylactic nodal irradiation (as opposed to tumour-bed irradiation only) as poor prognostic factors.

CONCLUSION

In patients undergoing poRT, radiotherapy parameters had little influence over their survival irrespective of patient, disease characteristics, and quality of resection. In patients undergoing RT, extended-field radiotherapy improved survival in addition to PS and nodal stage.

Soft Tissue Solitary Fibrous Tumor: Combined Surgery and Radiation Therapy Results in Excellent Local Control

PURPOSE

To report survival outcomes and local control in patients with solitary fibrous tumors (SFT) treated using surgery and radiation therapy (RT).

METHODS

We reviewed the medical records of 31 consecutive patients definitively treated for SFT with surgery and RT between 1982 and 2012. The median age was 51 years (range, 23 to 88 y) and tumors were evenly distributed between the head and neck (n=9, 29%), trunk (n=10, 32%), and lower extremities (n=9, 29%). The majority of tumors were large (>5 cm) (n=23, 72%). Specimens had a median of 2 mitoses/10 HPF (range, 0 to 8). Nearly half the cases were treated with postoperative RT (n=14, 45%; median dose, 58 Gy) and the other 17 patients (55%) received preoperative RT (median dose, 50 Gy).

RESULTS

Median follow-up time was 59 months (range, 18 to 349 mo). The 5-year rates of local control, overall survival, and distant metastatic-free survival were 100%, 95%, and 92%, respectively. There were no local or nodal relapses and the 10-year complication rate was 6% (n=2).

CONCLUSIONS

Treatment of soft tissue SFT using combined surgery and RT results in excellent local control.

Characteristics and Patterns of Rare Malignancies Published in Rare Tumors

Rare Tumors is an international peer-reviewed medical journal established in 2009. The journal is focused on rare cancers and aims to expand upon current knowledge on their presentation, diagnosis, management, and outcomes. We reviewed the 335 case reports published from 2009 to 2015. We found great diversity in both the country of origin as well as specialty of first authors. Outside of the United States (US) and European Union (EU), there were 20 countries with contributions to the journal. Similarly, there was representation from twelve medical specialties with first authorship of reports. Rare Tumors continues to encourage involvement from physicians across the globe and from all medical disciplines.

The Present and Future Opportunities of the Rare Cancer Network: An International Consortium for Advancement of Oncologic Care

To date, the Rare Cancer Network (RCN) has initiated more than 90 studies and 54 peer-reviewed publications were produced as a result. The Second International Symposium of the Rare Cancer Network recently took place in Istanbul, Turkey on April 17-18, 2015, and update was given on multiple currently ongoing projects, while also giving room for new proposals which will shape the direction of future studies for the group. This companion issue of the RCN Proceedings summarized the findings of this meeting, while also serving as a call for fresh projects and papers which will continue to energize the group and advance the oncologic science. A brief introduction to the principles, history, and vision of the RCN was also included. To review, the academic year of 2014-15 marked an enormous success for the international members of the RCN, with the generation of 8 fully published papers and more than 12 newly proposed topics. By the collective efforts of all RCN members, in the future, we look forward to the upcoming opportunities in continuing to advance the standard of chemo- and radiotherapeutic oncologic care for selected rare tumor topics. The studies of these rare cancers often do not allow the design and execution of prospectively enrolled trials; however, these uncommon malignancies do impact the humankind and add to its suffering globally in significant ways.