COPENHAGEN, DENMARK – Cancer survivors have more than double the risk of a second primary cancer of the same type, according to a study published in Canadian Medical Association Journal, whereas the risk of a second primary cancer of another type was only slightly elevated.

Danish researchers looked at data for the entire population of Denmark (7 493 705 people) from 1980 to 2007 to determine whether the risk of secondary cancer is linked to the type of cancer found in the first instance. About 10% — 765 255 people — had one or more diagnoses of primary cancer for a total of 843 118 diagnoses.

About 15% of cancer survivors worldwide are diagnosed with a second primary cancer.

The researchers found a 2.2-fold risk of a second primary cancer of the same type as the first in cancer survivors. The risk of a different type of second primary cancer was 1.1-fold. Risk varied depending on the type of cancer. The risk of a second cancer of the same type was reduced after prostate cancer and greatest after sarcoma. The risk of a second cancer of a different type was also reduced after prostate cancer and greatest after larynx cancer.

To understand the association between cancers, the researchers produced a table containing estimates of risk for all 27 cancers after all 27 first cancer types. They suggest that this catalogue might be valuable to further cancer studies.

“The striking contrast between the 2.2-fold increased risk of a second primary cancer being the same type as the first and the 1.1-fold increased risk of it being different from the first cancer suggests that characteristics of the individual patient were involved,” writes Dr. Stig Bojesen of Herlev Hospital, Copenhagen University Hospital and the University of Copenhagen, with coauthors. “The risk of a second primary cancer seems to be specific to cancer type and is probably driven by the patient’s genetic and lifestyle risk factors.”

They also looked at the association of the first cancer to smoking because it is known to increase the risks of many types of cancer. “We were surprised to see that in our study, the risk of other smoking-related cancers in patients surviving a smoking-related cancer was only 1.2-fold,” said Dr. Bojesen. “The good news is that in the individual cancer survivor, the increased risk of a new cancer is mainly confined to the same cancer as the first — even in people with an unhealthy lifestyle such as smoking.”

“We speculate that in general, risk factors acting over the long term seem to be type specific in the individual patient,” write the authors. “However, other explanations are also plausible: effects of treatment and an increase (or decrease) in diagnostic surveillance could change observed risk of cancer in the same organ as opposed to other organs.”

“Future studies of individual pairs of first and second primary cancers should clarify whether the association is due to shared genetic or lifestyle risk factors, codiagnosis of a primary cancer in close anatomic proximity to the first cancer, treatment of the first cancer or the timing of the diagnosis of the first cancer (in childhood v. adulthood),” the authors conclude.

In a related commentary, Dr. Marcy Winget from Alberta Health Services and coauthor write, “Nielsen and colleagues found that the risk of a second primary cancer depended greatly on the types of the first and second cancers; heterogeneity in risk was substantial across cancer types, regardless of whether the second cancer was the same type as the first.” They point out that this significant heterogeneity requires looking at risk for specific cancers by paired first and second cancers rather than overall risk.

“Caution must be exercised, however, in interpreting the findings for implications for clinical practice, in view of the substantial heterogeneity in risk.”

- MFP Wire Services
- 11-28-2011

By: Ed Susman

MIAMI BEACH, FL – Treatment with a chemotherapy plus radiation regimen for patients with high-risk soft-tissue sarcoma appear to show effective long-term local tumour control and amputation-free survival, researchers said at the 53rd Annual Meeting of the American Society for Radiation Oncology.

The 53rd Annual Meeting of the American Society for Radiation Oncology

“This pilot study demonstrates the feasibility of cyclophosphamide and etoposide-based chemoradiotherapy with excellent long-term local control and limb preservation,” said Daniel Indelicato, MD, Radiation Oncology, University of Florida Proton Therapy Institute, Jacksonville, Florida.

Dr. Indelicato and colleagues reviewed outcomes of 15 patients treated with the combination of chemotherapy and radiation and compared them with 30 case controls who were administered preoperative radiation but who were not given chemotherapy.

Patients receiving 2 cycles of concurrent chemotherapy and 4 cycles of adjuvant etoposide achieved a 10-year overall survival of 67% compared with an overall survival of 43% for the case-matched controls (P =.009).

The researchers also observed a trend towards improved cause-specific survival of 73% among those receiving chemotherapy compared with 55% for the case controls (P =.12).

All of the chemotherapy-treated patients achieved local control compared with 91% of the patients who did not receive chemotherapy (P =.29). About 93% of the chemotherapy-treated patients achieved local control and amputation-free survival compared with 85% of the case controls (P =.49). About 53% of the patients receiving chemotherapy achieved distant metastatic-free survival compared with 50% of the controls (P =.78).

However, the researchers also observed that if metastases could be excised, those patients who had chemotherapy were more likely to still achieve a disease cure. Three of the 7 chemotherapy-treated patients survived following surgery to remove the metastases compared with none of the 15 controls.

“The higher rate of cure observed in patients developing metastases following chemoradiotherapy requires further validation,” Dr. Indelicato noted.

Although haematologic toxicity was observed among the patients treated with chemotherapy, the rate of grade >3 grade complications was similar between the groups.

The chemotherapy regimen consisted of cyclophosphamide 300 mg/m2 plus etoposide 100 mg/m2 administered intravenously every 12 hours for 6 doses and days 1 to 3 of a 21-day cycle. Radiation was delivered at a dose of 50.4 Gy in 1.2-Gy fractions twice daily. The control patients were matched on size, tumour location, sex, disease grade, and T-stage.

Fifteen patients received 2 cycles of concurrent and 4 cycles of adjuvant chemotherapy with cyclophosphamide and etoposide as part of a novel preoperative chemoradiotherapy limb-conservation regimen for high-risk extremity soft-tissue sarcoma. All tumours were high-grade with a median size of 13 cm (range, 3-35 cm).

- MFP Wire Services
- 10-13-2011

By: Ed Susman

MIAMI BEACH, FL – Analysis of one of the largest case series involving adults with Ewing’s sarcoma indicates that local control of the tumour is especially poor and suggests that more aggressive local therapy may be necessary in adults than in children, researchers reported at the 53rd Annual Meeting of the American Society for Radiation Oncology.

The 53rd Annual Meeting of the American Society for Radiation Oncology

“Survival and local control outcomes in adult patients with Ewing’s sarcoma are inferior to recent multi-institutional results in children,” reported Safia Ahmed, Mayo Clinic Medical School, Rochester, Minnesota.

The researchers reviewed 30 years of records at the Mayo Clinic dating back to 1977 and identified 163 adult patients diagnosed with Ewing’s sarcoma. Of those, 122 had localised disease and 41 patients had cancer that had already metastasised when first seen at the Mayo clinic. Two-thirds of the patients were male, and median age at diagnosis was 28 years.

“We are reporting the largest retrospective single institution experience of 163 Ewing’s sarcoma patients of at least 18 years of age,” the authors noted in their poster presentation.

The analysis found that, not surprisingly, the outcomes for those patients with localised disease at presentation were superior to patients with metastatic Ewing’s sarcoma. The 5-year overall survival was 54% among patients who did not have metastatic disease compared with 10% for those patients whose disease was advanced (P =.0001). This compares with an overall survival of about 75% among paediatric patients with Ewing’s sarcoma.

Similarly, event-free survival was achieved by 38% of the patients with localised disease, but only by 9% of those with metastatic disease (P =.0001).

Surgery was the most common modality for local control with 42% of the patients who presented with localised tumours being treated in that fashion. About 22% of patients were treated with radiotherapy. Another 35% of the patients were treated with both surgery and radiation.

Event-free survival among the patients who underwent surgery was 48%, while 24% of those who underwent radiation therapy alone achieved a 5-year event-free survival, and 36% of patients who received both treatment modalities had event-free survival after 5 years. However, the differences in outcomes did not achieve statistical significance (P =.42).

“Improved outcomes require more effective systemic therapy and a better understanding of the biologic and molecular differences between adult and paediatric Ewing’s sarcoma,” the researchers suggested.

- MFP Wire Services
- 10-12-2011