Carmen Martos

Risk of second cancer among women with breast cancer

A large number of women survive a diagnosis of breast cancer. Knowledge of their risk of developing a new primary cancer is important not only in relation to potential side effects of their cancer treatment, but also in relation to the possibility of shared etiology with other types of cancer. A cohort of 525,527 women with primary breast cancer was identified from 13 population‐based cancer registries in Europe, Canada, Australia and Singapore, and followed for second primary cancers within the period 1943–2000. We used cancer incidence rates of first primary cancer for the calculation of standardized incidence ratios (SIRs) of second primary cancer. Risk of second primary breast cancer after various types of nonbreast cancer was also computed. For all second cancer sites combined, except contralateral breast cancer, we found a SIR of 1.25 (95% CI = 1.24–1.26) on the basis of 31,399 observed cases after first primary breast cancer. The overall risk increased with increasing time since breast cancer diagnosis and decreased by increasing age at breast cancer diagnosis. There were significant excesses of many different cancer sites; among these the excess was larger than 150 cases for stomach (SIR = 1.35), colorectal (SIR = 1.22), lung (SIR = 1.24), soft tissue sarcoma (SIR = 2.25), melanoma (SIR = 1.29), non‐melanoma skin (SIR = 1.58), endometrium (SIR = 1.52), ovary (SIR = 1.48), kidney (SIR = 1.27), thyroid gland (SIR = 1.62) and leukaemia (SIR = 1.52). The excess of cancer after a breast cancer diagnosis is likely to be explained by treatment for breast cancer and by shared genetic or environmental risk factors, although the general excess of cancer suggests that there may be additional explanations such as increased surveillance and general cancer susceptibility.

Risk of second primary cancer among patients with head and neck cancers: A pooled analysis of 13 cancer registries.

The objective of the study was to assess the risk of second primary cancers (SPCs) following a primary head and neck cancer (oral cavity, pharynx and larynx) and the risk of head and neck cancer as a SPC. The present investigation is a multicenter study from 13 population‐based cancer registries. The study population involved 99,257 patients with a first primary head and neck cancer and contributed 489,855 person‐years of follow‐up. To assess the excess risk of SPCs following head and neck cancers, we calculated standardized incidence ratios (SIRs) by dividing the observed numbers of SPCs by the expected number of cancers calculated from accumulated person‐years and the age‐, sex‐ and calendar period‐specific first primary cancer incidence rates in each of the cancer registries. During the observation period, there were 10,826 cases of SPCs after head and neck cancer. For all cancer sites combined, the SIR of SPCs was 1.86 (95% CI = 1.83–1.90) and the 20‐year cumulative risk was 36%. Lung cancer contributed to the highest proportion of the SPCs with a 20‐year cumulative risk of 13%. Excess second head and neck cancer risk was observed 10 years after diagnosis with lymphohaematopoietic cancers. The most common SPC following a first primary head and neck cancer was lung cancer. However, the highest excess of SPCs was in the head and neck region. These patterns were consistent with the notion that the pattern of cancer in survivors of head and neck cancer is dominated by the effect of tobacco smoking and alcohol drinking.

Second primary cancers among 109 000 cases of non-Hodgkin's lymphoma

An analysis of other primary cancers in individuals with non-Hodgkins lymphoma (NHL) can help to elucidate this cancer aetiology. In all, 109 451 first primary NHL were included in a pooled analysis of 13 cancer registries. The observed numbers of second cancers were compared to the expected numbers derived from the age-, sex-, calendar period- and registry-specific incidence rates. We also calculated the standardised incidence ratios for NHL as a second primary after other cancers. There was a 47% (95% confidence interval 43–51%) overall increase in the risk of a primary cancer after NHL. A strongly significant (P<0.001) increase was observed for cancers of the lip, tongue, oropharynx*, stomach, small intestine, colon*, liver, nasal cavity*, lung, soft tissues*, skin melanoma*, nonmelanoma skin*, bladder*, kidney*, thyroid*, Hodgkins lymphoma*, lymphoid leukaemia* and myeloid leukaemia. Non-Hodgkins lymphoma as a second primary was increased after cancers marked with an asterisk. Patterns of risk indicate a treatment effect for lung, bladder, stomach, Hodgkins lymphoma and myeloid leukaemia. Common risk factors may be involved for cancers of the lung, bladder, nasal cavity and for soft tissues, such as pesticides. Bidirectional effects for several cancer sites of potential viral origin argue strongly for a role for immune suppression in NHL.

Second malignancies among survivors of germ-cell testicular cancer: A pooled analysis between 13 cancer registries

We investigated the risk of second malignancies among 29,511 survivors of germ‐cell testicular cancer recorded in 13 cancer registries. Standardized incidence ratios (SIRs) were estimated comparing the observed numbers of second malignancies with the expected numbers obtained from sex‐, age‐, period‐ and population‐specific incidence rates. Seminomas and nonseminomas, the 2 main histological groups of testicular cancer, were analyzed separately. During a median follow‐up period of 8.3 years (0–35 years), we observed 1,811 second tumors, with a corresponding SIR of 1.65 (95% confidence interval (CI): 1.57–1.73). Statistically significant increased risks were found for fifteen cancer types, including SIRs of 2.0 or higher for cancers of the stomach, gallbladder and bile ducts, pancreas, bladder, kidney, thyroid, and for soft‐tissue sarcoma, nonmelanoma skin cancer and myeloid leukemia. The SIR for myeloid leukemia was 2.39 (95% CI: 1.41–3.77) after seminomas, and 6.77 (95% CI: 4.14–10.5) after nonseminomas. It increased to 37.9 (95% CI: 18.9–67.8; based on 11 observed cases of leukemia) among nonseminoma patients diagnosed since 1990. SIRs for most solid cancers increased with follow‐up duration, whereas they did not change with year of testicular cancer diagnosis. Among subjects diagnosed before 1980, 20 year survivors of seminoma had a cumulative risk of solid cancer of 9.6% (95% CI: 8.7–10.5%) vs. 6.5% expected, whereas 20 years survivors of nonseminoma had a risk of 5.0% (95% CI: 4.2–6.0%) vs. 3.1% expected. In conclusion, survivors of testicular cancers have an increased risk of several second primaries, where the effect of the treatment seems to play a major role.

Second primary malignancies in patients with male breast cancer.

An international multicentre study of first and second primary neoplasms associated with male breast cancer was carried out by pooling data from 13 cancer registries. Among a total of 3409 men with primary breast cancer, 426 (12.5%) developed a second neoplasia; other than breast cancer, a 34% overall excess risk of second primary neoplasia, affecting the small intestine (standardised incidence ratio, 4.95, 95% confidence interval, 1.35–12.7), rectum (1.78, 1.20–2.54), pancreas (1.93, 1.14–3.05), skin (nonmelanoma, 1.65, 1.16–2.29), prostate (1.61, 1.34–1.93) and lymphohaematopoietic system (1.63, 1.12–2.29). A total of 225 male breast cancers was recorded after cancers other than breast cancer, but an increase was found only after lymphohaematopoietic neoplasms. BRCA2 (and to some extent BRCA1) mutations may explain the findings for pancreatic and prostate cancers. Increases at other sites may be related to unknown factors or to chance. This large study shows that the risks for second discordant tumours after male breast cancer pose only a moderate excess risk.

Risk of Second Primary Cancer among Esophageal Cancer Patients: a Pooled Analysis of 13 Cancer Registries

Background: The objective of this study is to assess the risk of second primary cancers following a first primary esophageal cancer as well as the risk of esophageal cancer as a second primary, following first primary cancers of other sites. Methods: The present investigation is a multicenter study of 13 population-based cancer registries in Europe, Australia, Canada, and Singapore. To assess excess occurrence of second cancers after esophageal cancers, we calculated standardized incidence ratios (SIR) by dividing the observed numbers of second cancers by the expected number of cancers calculated from the accumulated person-years and the age-, sex-, calendar period-, and registry-specific first primary cancer incidence rates. Results: During the study period, 959 cases of second primary cancers occurred after an initial esophageal cancer, resulting in a SIR of 1.15 (95% confidence interval, 1.08-1.22). Second primary stomach cancers were associated with first primary esophageal adenocarcinomas (SIR, 2.13; 95% confidence interval, 1.26-3.37) and second primary cancers of the oral cavity and pharynx (6.68; 5.33-8.26), stomach (1.53; 1.14-2.01), larynx (3.24; 1.88-5.18), lung (1.55; 1.28-1.87), kidney (1.88; 1.18-2.85), and thyroid (2.92; 1.18-6.02) were associated with first primary squamous cell carcinomas of the esophagus. An excess of esophageal cancer as a second primary were observed following first primary cancers of the aerodigestive tract, female breast, cervix, testis, bladder, Hodgkins lymphoma, and non–Hodgkin lymphoma. Conclusion: We observed associations of esophageal cancer with second primary head and neck cancers and lung cancer regardless of years of follow-up, which may suggest that common risk factors play a role in multiple tumor development. (Cancer Epidemiol Biomarkers Prev 2008;17(6):1543–9)

Associations between small intestine cancer and other primary cancers: An international population-based study

Cancer of the small intestine is a rare neoplasm, and its etiology remains poorly understood. Analysis of other primary cancers in individuals with small intestine cancer may help elucidate the causes of this neoplasm and the underlying mechanisms. We included 10,946 cases of first primary small intestine cancer from 13 cancer registries in a pooled analysis. The observed numbers of 44 types of second primary cancer were compared to the expected numbers derived from the age‐, gender‐ and calendar period‐specific cancer incidence rates in each registry. We also calculated the standardized incidence ratios (SIR) for small intestine cancer as a second primary after other cancers. There was a 68% overall increase in the risk of a new primary cancer after small intestine carcinoma (SIR = 1.68, 95% confidence interval [CI] = 1.47–1.71), that remained constant over time. The overall SIR was 1.18 (95% CI = 1.05–1.32) after carcinoid, 1.29 (1.01–1.63) after sarcoma, and 1.27 (0.78–1.94) after lymphoma. Significant (p < 0.05) increases were observed for cancers of the oropharynx, colon, rectum, ampulla of Vater, pancreas, corpus uteri, ovary, prostate, kidney, thyroid gland, skin and soft tissue sarcomas. Small intestine cancer as a second primary was increased significantly after all these cancers, except after oropharyngeal and kidney cancers. Although some of the excess may be attributable to overdiagnosis, it is plausible that most additional cases of second primary cancers were clinically relevant and were due to common genetic (e.g., defects in mismatch or other DNA repair pathways) and environmental (e.g., dietary) factors.

Second primary cancers in patients with nasopharyngeal carcinoma: a pooled analysis of 13 cancer registries

ObjectiveTo study the risk of second primary cancers in nasopharyngeal carcinoma (NPC) patients and the risk of NPC as second primary cancer.MethodsWe used data from the cancer registries from Singapore and from 12 low-incidence areas, including a total of 8,947 first occurring NPC cases, and 167 second occurring cases. We calculated standardized incidence ratios (SIRs) by comparing the second cancer incidence in NPC patients to the first primary cancer incidence in non-cancer population. We also calculated SIRs of second NPC after other primaries.ResultsIn Singapore, the risk of cancers of the lung (SIR = 0.42), stomach (SIR = 0.41), and colon (SIR = 0.23) was significantly decreased after NPC, whereas that of cancer of the tongue (SIR = 11.1) was significantly increased. In Australia, Canada, and Europe, the risk of non-Hodgkin’s lymphoma (NHL) (SIR = 3.06), tongue cancer (SIR = 5.29), brain cancer (SIR = 3.89), myeloid leukemia (SIR = 3.85), and non-melanoma skin cancer (NMSC) (SIR = 3.47) was significantly increased after NPC. Incidences of second occurring NPCs following various primary cancers were not significantly altered compared to the incidence of first occurring NPCs.ConclusionsImmune suppression (NHL, NMSC), shared genetic factors (lung cancer, NHL, myeloid leukemia), and shared environmental risk factors (tongue and brain cancers) might explain the associations. Except for NHL, there was no evidence of association with other Epstein-Barr virus-related cancers.

Associations between ocular melanoma and other primary cancers: An international population‐based study

Ocular melanoma is a rare neoplasm with a poorly understood etiology, especially concerning its link with ultraviolet‐light exposure. Studying the risk of second primary cancers may help to formulate causal hypotheses. We used data from 13 cancer registries, including 10,396 first occurring ocular melanoma cases, and 404 second occurring cases. To compare the second cancer incidence in ocular melanoma patients to that in noncancer population, we calculated standardized incidence ratios (SIRs) of 32 types of cancer. We also calculated SIRs of second ocular melanoma after other primaries. Ocular melanoma patients had significantly increased risk of cutaneous melanoma (SIR = 2.38, 95% CI 1.77–3.14), multiple myeloma (SIR = 2.00, 1.29–2.95), and of liver (SIR = 3.89, 2.66–5.49), kidney (SIR = 1.70, 1.22–2.31), pancreas (SIR = 1.58, 1.16–2.11), prostate (SIR = 1.31, 1.11–1.54), and stomach (SIR = 1.33, 1.03–1.68) cancers. Risks of cutaneous melanoma were highly variable between registries and were mainly increased in females, in younger patients, in first years following diagnosis, and for patients diagnosed after 1980. The risk of ocular melanoma was significantly increased only after prostate cancer (SIR = 1.41, 1.08–1.82). Risk of cutaneous melanoma after ocular melanoma had epidemiological patterns, similar to cutaneous melanoma screening in the general population. The increased risk of cutaneous melanoma would be largely due to greater skin cancer surveillance in ocular melanoma patients, and not to common etiological factors. The high SIR found for liver cancer may be explained by misclassification bias. Common etiological factors may be involved in ocular and prostate cancers.

Risk of second malignant neoplasms after childhood central nervous system malignant tumours: an international study.

PURPOSE The aim of this study was to assess the risk of second malignant neoplasms (SMNs) other than central nervous system (CNS) neoplasms after childhood CNS cancer in an international multicentre study. METHODS Individual data on cases of CNS cancer in children (0-14 years) and on subsequent SMNs were obtained from 13 population-based cancer registries contributing data for different time periods in 1943-2000. Standardised incidence ratios (SIRs) with 95% confidence intervals (CI), absolute excess risk and cumulative incidence of SMNs were computed. RESULTS We observed 43 SMNs in 8431 CNS cancer survivors. The SIR was 10.6 (4.85-20.1) for thyroid cancer (nine cases), 2.75 (1.01-5.99) for leukaemia (six cases) and 2.47 (0.90-5.37) for lymphoma (six cases). The SIRs were highest in the first 10 years after CNS cancer diagnosis. The cumulative incidence of non-CNS SMNs was 3.30% (0.95-5.65%) within 45 years after a CNS cancer diagnosis. Within 15 years, the cumulative incidence was highest for cases diagnosed after 1980 (0.56%, 95% CI: 0.29-0.82%). CONCLUSION This population-based study indicates that about one every 180 survivors of a childhood CNS cancer will develop a non-CNS SMN within the following 15 years. The excess is higher after glioma and embryonal malignant tumour than after another CNS tumour.