Incidence Of Multiple Cancers Research Articles

Chronic hepatitis C infection is associated with higher incidence of extrahepatic cancers in a Canadian population based cohort.

IntroductionChronic infection with hepatitis C virus (HCV) is an established risk factor for liver cancer. Although several epidemiologic studies have evaluated the risk of extrahepatic malignancies among people living with HCV, due to various study limitations, results have been heterogeneous.MethodsWe used data from the British Columbia Hepatitis Testers Cohort (BC-HTC), which includes all individuals tested for HCV in the Province since 1990. We assessed hepatic and extrahepatic cancer incidence using data from BC Cancer Registry. Standardized incidence ratios (SIR) comparing to the general population of BC were calculated for each cancer site from 1990 to 2016.ResultsIn total, 56,823 and 1,207,357 individuals tested positive and negative for HCV, respectively. Median age at cancer diagnosis among people with and without HCV infection was 59 (interquartile range (IQR): 53-65) and 63 years (IQR: 54-74), respectively. As compared to people living without HCV, a greater proportion of people living with HCV-infection were men (66.7% vs. 44.7%, P-value <0.0001), had comorbidities (25.0% vs. 16.3%, P-value <0.0001) and were socially deprived (35.9% vs. 25.0%, P-value <0.0001). The SIRs for liver (SIR 33.09; 95% CI 29.80-36.39), anal (SIR: 2.57; 95% CI 1.52-3.63), oesophagus (SIR: 2.00; 95% CI 1.17-2.82), larynx (SIR: 3.24; 95% CI 1.21-5.27), lung (SIR: 2.20; 95% CI 1.82-2.58), and oral (SIR: 1.78; 95% CI 1.33-2.23) cancers were significantly higher among individuals living with HCV. The SIRs for bile duct and pancreatic cancers were significantly elevated among both individuals living with (SIR; 95% CI: 2.20; 1.27-3.14; 2.18; 1.57-2.79, respectively) and without HCV (SIR; 95% CI: 2.12; 1.88-2.36; 1.20; 1.11-1.28, respectively).Discussion/ConclusionIn this study, HCV infection was associated with increased incidence of several extrahepatic cancers. The elevated incidence of multiple cancers among negative HCV testers highlights the potential contributions of screening bias and increased cancer risks associated with factors driving acquisition of infection among this population compared to the general population. Early HCV diagnosis and treatment as well as public health prevention strategies are needed to reduce the risk of extrahepatic cancers among people living with HCV and potentially populations who are at higher risk of HCV infection.

Geospatial analysis of multiple cancers in individuals in the US, 2004-2014.

Background:There is a projected rapid increase in cancer survivors in the US population, from 15.5 million in 2016 to 26.1 million by 2040. Improvements in treatment and detection have led to increased survival, however, there is now a risk of developing new cancers as a result of environment toxins, behavioral risk factors, genetic predisposition, and late-term effects of radiation and chemotherapeutic treatments. This study takes a geospatial approach to examining the place of occurrence of multiple cancers originating in the population of four screenable cancers—female breast, colorectal, prostate, and cervical cancers—among the US population.Methods:During 2004–2014, 6,523,532 primary cancer patients with one of these four screenable cancers were examined, and subsequent primary cancers (multiple cancers of any type) were noted. Individual level analyses estimated the odds of diagnosis with multiple cancers controlling for age, sex, and race-ethnicity. Change in effects on odds of multiple cancer diagnoses with age, sex, and race-ethnicity were evaluated controlling separately for late-stage diagnosis of the primary cancer or each primary cancer diagnosis type. County-level spatial cluster analysis was employed to identify and visualize higher than average multiple cancer rates.Results:Over half of the study population were female and almost 30% of the study population were diagnosed at late-stage for their first cancer. Multiple occurrences of all cancers increased during the time period for patients with initial breast or colorectal cancers. Among BC primary cancer cases, subsequent multiple cancers were mostly new breast cancers. By contrast, for CRC primary cancer cases, subsequent multiple cancers were about equally likely to be new CRC cases or other cancer types. Sex, age and race-ethnicity were all significantly associated with multiple cancers. In the model controlling for CRC as the primary type, the age and race-ethnicity effects were somewhat different than for all the other models. Thus, there was something distinctly different about the multiple cancer incidence among patients with CRC as their primary cancer as compared to patients with BC, CVC, or PC primaries. In subsequent analyses by county, there were distinct geospatial patterns in multiple cancer rates with most high-rate clusters occurring in the north- and mid-west US.Conclusions:There were distinct individual level and geospatial disparities in multiple cancer diagnoses for the study population of all primary breast, colorectal, cervical, or prostate cancer patients during the decade studied. It is importance to emphasize continued screening for cancer survivors and research on personal and environmental drivers of multiple primary cancers.

Abstract 979: Programmed death-ligand 1 expression and tumor-infiltrating immune cells in cancers associated with Li-Fraumeni syndrome

Abstract Purpose: Li-Fraumeni syndrome (LFS), due to TP53 germline mutations, is characterized by high incidence of multiple cancers. Dysregulation of the TP53 pathway is associated with changes in chemokine production and reduced tumor immune infiltration in some cancer types. Recent works also suggested that TP53 negatively regulates PDL1 expression through the non-coding RNA miR-34. To better understand immune evasion of LFS spectrum cancers and to explore the feasibility of PD1/PDL1 targeted therapies as an alternative to genotoxic treatments in LFS patients, we investigated a range of LFS-related tumor types for PDL1 expression and tumor-infiltrating immune cells. Methods: We retrospectively collected a total of 72 tumor samples (osteosarcoma=32, rhabdomyosarcoma=11, adrenocortical carcinoma=11 and breast carcinoma=18) from 60 pediatric and adult patients identified through the LFS French database and direct contact with oncologic centers. Immunochemistry analyses were performed on whole slide sections. PDL1 staining was performed using the clone E1L3N (Cell Signaling Technology) according to the standard automated protocols. Immune infiltrate was characterized by the following antibody panel: CD8, FOXP3 and CD68. For CD8+ and FoxP3+ T cells, cell density per surface unit was determined by cell counting; for CD68+ macrophages, a semi-quantitative scoring (from 0 to 4) was performed. Results: Median age of patients was 13 years (range: 6-23) for osteosarcoma, 1.7 years (range: 0.8-5) for rhabdomyosarcoma, 2.3 years (range: 0.4-6) for adrenocortical carcinoma and 27.5 years (range: 22-54) for breast carcinoma. Seven patients presented ≥2 metachronous tumors. Biopsy was performed at diagnosis for 68 patients, at relapse for 3 patients and at early progression for one patient. None of the samples presented any detectable PDL1 expression neither on tumor cells nor on tumor microenvironment. Low/very low amount of CD8+ cytotoxic T-cells was displayed, regardless of the histology. FoxP3+ regulatory T-cell infiltration varied among tumor types. Thirty-five/72 tumors (49%) did not contain regulatory T cells. Breast carcinomas presented significant amounts of regulatory T cells (16/18, 89%), but at low density for 10 out of 16 samples (62%). Sixty-two/72 tumors (86%) presented CD68+ macrophage infiltrates, with high density in 37/62 (60%) of them (score ≥ 2+). Conclusion: The absence of PDL1 expression on tumor cells and microenvironment as well as the low amount of regulatory T cells do not support the hypothesis of PDL1 induction through p53 inactivation in LFS. The role of innate immunity needs to be explored to identify alternative immunological targets. Citation Format: Emilie Saucier, Claudia Pasqualini, Louise Galmiche, Frédérique Larousserie, Marie Karanian, Véronique Minard-Colin, Birgit Geoerger, Dominique Valteau-Couanet, Laurence Brugières, Jean-Yves Scoazec. Programmed death-ligand 1 expression and tumor-infiltrating immune cells in cancers associated with Li-Fraumeni syndrome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 979.

Rola weryfikacji histopatologicznej, trudności terapeutyczne i leczenie przeciwzakrzepowe w paliatywnej chemioterapii chorej z niedoborem antytrombiny oraz rakiem jelita grubego i rakiem macicy w wywiadzie

Palliative chemotherapy in patients with thrombophilia is a challenge for clinical oncologists. On one hand the optimal treatment should be very safe for patient, on the other hand – as effective as possible. That therapy is also connected with proper thromboprophylaxis. The incidence of multiple cancers is a serious problem of modern oncology. In patients whose medical history includes two or more cancers, it is essential to obtain histopathological diagnosis before the administration of treatment of disseminated disease. It allows to avoid improper therapy which is often toxic. The article presents the case of a patient with antithrombin deficiency and two cancers in medical history: colon cancer and endometrial cancer. The treatment of the patient because of the metastatic cancer was started after the histopathological diagnosis. In metastatic lymph node the endometrial cancer was recognized. The carboplatin and paclitaxel were used in the therapy. The treatment was conducted in four course chemotherapy. It revealed considerable polyneuropathy and hematologic toxicity limiting from further therapy. Treatment allowed to obtain biochemical response, decrease of metastases and the condition of a patient improved. During the systemic therapy thromboprophylaxis with acenocumarol was used. The incidence of venous thromboembolism or bleeding complications were not noticed.

Metastatic colorectal cancer in a cirrhotic liver with synchronous hepatocellular carcinoma.

We are reporting a case of a patient with a previous history of colorectal cancer (CRC) and cirrhosis, who developed concurrent liver lesions consistent with hepatocellular carcinoma (HCC); a case which is unique due to the low incidence of multiple cancers, particularly HCC in the setting of previous advanced colorectal carcinoma along, in a cirrhotic liver. We will review the known literature on multiple cancer rates found in patients with known colorectal carcinoma. We will then outline this particular patient's presentation, followed by a discussion as to why the particular concurrent development of HCC in the setting of previous CRC is of note.

Germline BAP1 mutation in a family with high incidence of multiple primary cancers and a potential gene–environment interaction

We report a high-risk cancer family with multiple mesotheliomas, cutaneous melanomas, basal cell carcinomas, and meningiomas segregating with a germline nonsense mutation in BAP1 (c.1938T>A; p.Y646X). Notably, most (four of five) mesotheliomas were peritoneal rather than the usually more common pleural form of the disease, and all five mesothelioma patients also developed second or third primary cancers, including two with meningiomas. Another family member developed both cutaneous melanoma and breast cancer. Two family members had basal cell carcinomas, and six others had melanocytic tumors, including four cutaneous melanomas, one uveal melanoma, and one benign melanocytic tumor. The family resides in a subtropical area, and several members had suspected exposure to asbestos either occupationally or in the home. We hypothesize that the concurrence of a genetic predisposing factor and environmental exposure to asbestos and UV irradiation contributed to the high incidence of multiple cancers seen in this family, specifically mesothelioma and various uveal/skin tumors, respectively.

Clinical characteristics of multiple primary cancer associated with esophageal squamous carcinoma

To examine the characteristics of esophageal squamous cancers with multiple primary cancers in another organ. Between January 2012 and December 2014, 3 104 patients with esophageal squamous cell carcinoma treated in Cancer Institute and Hospital, Chinese Academy of Medical Sciences, were reviewed for the presence of an additional primary cancer retrospectively. The patients were divided into two groups according to whether they had multiple primary cancer. Totally 369 (11.9%) patients were found multiple primary cancer in the other organs. Among these patients, 72.4% was found synchronously, another primary cancer was found in the head and neck region in 211 (6.8%), in the stomach in 140 (4.2%), and in the lung, colon, breast, and other locations in the remaining patients. Of the 211 patients with another primary cancer in the head and neck region, 156 (73.2%) had hypopharyngeal cancer. Furthermore, the incidence of intraesophageal multiple cancerous lesion in the patients with primary cancer in the head and neck region was significantly higher than that in those whose other primary cancers were gastric cancer or in those with non-multiple primary cancer (P<0.01). There is a high incidence of multiple primary cancers in patients with esophageal squamous carcinoma, mostly found synchronously. The leading multiple primary cancers were head and neck cancer and stomach cancer. Intraesophageal multiple cancerous lesion is an indicator for a second primary cancer in head and neck. A better knowledge of the relationships between esophageal carcinoma and cancers in other organs may lead to earlier detection of other primary cancers and improved therapeutic results.

Bayesian factor analysis for spatially correlated data: application to cancer incidence data in Scotland

A hierarchical Bayesian factor model for multivariate spatially correlated data is proposed. Multiple cancer incidence data in Scotland are jointly analyzed, looking for common components, able to detect etiological factors of diseases hidden behind the data. The proposed method searches factor scores incorporating a dependence within observations due to a geographical structure. The great flexibility of the Bayesian approach allows the inclusion of prior opinions about adjacent regions having highly correlated observable and latent variables. The proposed model is an extension of a model proposed by Rowe (2003a) and starts from the introduction of separable covariance matrix for the observations. A Gibbs sampling algorithm is implemented to sample from the posterior distributions.

Highlights from Recent Cancer Literature

Highlights from Recent Cancer Literature

1173 Surveillance Strategy After Endoscopic Submucosal Dissection for Early Gastric Cancer: A Multicenter Study by Osaka University ESD Study Group

Endoscopic submucosal dissection (ESD) has been accepted as a treatment for early gastric cancer (EGC). However, it is known that the patient after endoscopic treatment of EGC is at risk of synchronous and metachronous multiple cancers, even though initial lesion is completely resected, and there is not enough evidence concerning surveillance strategy after ESD for EGC. The aim of this multicenter study is to clarify the surveillance strategy after ESD by assessing the incidence of multiple cancers during follow-up.

SELF‐LIMITING RISK OF METACHRONOUS GASTRIC CANCERS AFTER ENDOSCOPIC RESECTION

Since endoscopic resection (ER) has been established as a treatment for early gastric cancer, metachronous multiple cancers have become a problem. It is unclear whether the risk of metachronous cancer is self-limiting or permanent. The aim of this study was to evaluate the incidence of multiple cancers after ER during a long-term follow-up study. A total of 234 patients who received initial ER for early gastric cancers were evaluated retrospectively. ER included endoscopic mucosal resection and endoscopic submucosal dissection. Patients were followed up with endoscopy for 3.0-19.6 years (median, 5.0 years), including 40 patients surveyed for more than 10 years. Accessory cancers detected after ER, but which could be retrospectively viewed in pre-ER pictures, were evaluated in the metachronous group. Thirty patients (12.8%) developed 36 metachronous multiple cancers. The median interval between the discovery of metachronous cancer and the initial ER was 3.2 years; the longest interval was 9.7 years. Eight (22.2%) of the 36 metachronous cancers could be detected retrospectively in the picture record from pre-ER. The Kaplan-Meier curve of cumulative incidence of metachronous cancers stopped increasing after 10 years of follow up. Although the residual gastric mucosa after ER is thought to be a high-risk environment, the high risk may only be the result of occult synchronous cancers. It is probable that the high risk of metachronous cancers is not continuous after 10 years.

Clinical features of ulcerative colitis-associated colorectal cancer in Japan: an analysis of 169 cases over 20 years

13544 Background: Development of colorectal cancer is a well-known long-term complication of ulcerative colitis (UC). However, specific clinical features of UC-associated colorectal cancer have been controversial mainly due to the small number of cases, especially in the Asian countries. This study aims to clarify the clinicopathological features of UC-associated colorectal cancer compared with non-UC-associated colorectal cancer in Japan, using a large nationwide database. Methods: All patients pathologically diagnosed as colorectal cancer from 1978 to 1998 were extracted from the nationwide database, “Multi-Institutional Registry of Large-Bowel Cancer in Japan”, which covers almost 10% of all colorectal cancers in Japan. Clinicopathological factors were compared between those associated with UC and the others. Survival analysis in each TNM stage was performed using the Kaplan-Meier method. Results: Among 108,536 cases of colorectal tumors registered from 1978 to 1998, a total of 169 cases of UC-associated colorectal cancers were identified. All cases were from the Asian population. UC-associated cases showed higher prevalence of females, younger age, higher incidence of multiple cancers, and higher incidence of mucinous adenocarcinomas. On the other hand, there were no differences in tumor sites, family history of colorectal cancer, lymph node metastasis, distant metastasis, TNM stage, and CEA level adjusted by TNM stage between the two groups. Survival analysis revealed poorer prognosis in UC-associated colorectal cancers at TNM stage 3. Conclusions: UC-associated colorectal cancer showed unique histological features compared with usual colorectal cancer. The survival of UC-associated colorectal cancer with lymph node metastasis was poorer than usual colorectal cancer, and therefore, intensive adjuvant therapy and close follow-up is needed after surgery in this patient group. No significant financial relationships to disclose.

Incidence, diagnosis and significance of multiple gastric cancer.

Of 2790 patients with gastric cancer undergoing surgery between January 1978 and December 1993, 160 (with 356 neoplastic lesions) had synchronous multiple cancer. Of these lesions 271 (76 percent) were early cancers. Only 85 (53 percent) of the 160 patients were diagnosed before operation as having multiple cancer; 69 further patients (43 percent) were diagnosed during the course of the operation. Small flat (IIb) and depressed (IIc) type lesions had a propensity to be missed before operation. The incidence of multiple cancer was relatively low, indicating that several microscopic lesions might have been overlooked in this series. There has, however, only been one patient (1 percent) with subsequent cancer of the gastric remnant of 126 with multiple cancer and postoperative gastric remnants over the past 16 years. This might be because of co-resection of unrecognized lesions by distal gastrectomy in 68 percent of the patients. Alternatively some microscopic cancers might not invariably be destined to grow into clinically significant lesions over 10 or more years.

Pathologic characteristics of colorectal cancer in the elderly: a retrospective study of 947 surgical cases.

To determine the pathologic characteristics of colorectal cancer in the very old, a retrospective study of 947 consecutive Japanese patients aged > or =65 with 1,039 lesions were examined. Pathologic findings in the very old group (>85 years, n = 140) were compared with those in the younger groups; young-old group (65-74 years, n = 352) and middle-old group (75-84 years, n = 455). Although male:female ratio significantly decreased with advancing age, reaching 1:1.8 in the very old group, the relative odds of colorectal cancer in men were higher than that in women in all age groups. In the very old group, cancer of the proximal colon (proximal to the splenic flexure) accounted for 52% in women and 37% in men, being significantly higher than those in the younger groups. Proximal colonic cancers increased with advancing age in both genders. Higher proportions of poorly differentiated adenocarcinoma, mucinous carcinoma, cancer >5 cm in size, and protruding type cancer were present in the very old group, although these kinds of tumors typically occur in the proximal colon. The incidence of multiple cancers in the large intestine was not different among any age group (average, 8.6%). These results indicated that, even in the very old, colorectal cancers showed marked proximal excess, being explained by effect of both age and gender, and that the proximal shift may influence the proportion of histologic type and size of the tumor. These findings have important implications for screening and diagnosis of colorectal cancer in the elderly.

Multiple primary cancers of oral cavity and pharynx

Multiple primary cancers were found in 23 of 68 patients (34%) with an index cancer in the oral cavity or pharyngeal area treated in our institute from June 1995 to July 1998. Four cases had triple primary cancers. All 68 cases underwent upper and lower gastrointestinal endoscopy as well as ultrasonography of the liver. Lung CT was performed in cases with abnormal findings on chest roentgenograms. Multiple cancers were found in 5 of 25 oral cavity cases (20%), 6 of 14 mesopharynx cases (43%) and 12 of 29 hypopharynx cases (41%). Nine of 23 cases (39%) were synchronous and 14 (61%) were metachronous. Eighteen of 27 (69%) secondary cancers occurred in the upper aerodigestive tract with an especially high incidence (22%) in the esophagus. Gastroendoscopy also revealed 7 neoplastic lesions, aside from cancers, with the total abnormal rate of 24% (24/68). Thus, gastroendoscopy is useful for the diagnosis of multiple primary cancers. The frequency of multiple primary cancers in males (33%) was not different from that in females (35%). The average age of multiple primary cancer patients (65.1 years) was a little higher than that of single cancer patient (62.7 years). Smoking or drinking was not related to the incidence of multiple cancers. The interval between the first and the second cancer in metachronous cancer cases was 25.5 months on average, and within 4 years in 71% (10/14) of the cases. This result suggests that close follow-up including endoscopy should be required for at least 4 years after treatment of oral or pharyngeal cancer. Radical treatment for each of the multiple cancer lesions was performed in 22 of 23 cases, and the mortality rate of multiple primary cancer cases was not significantly different from that of single cancer cases. Among 7 cases who died of disease, 5 cases died of distant metastasis, suggesting that control of distant metastasis is an important issue in the treatment of multiple primary cancers.

RFLP ANALYSIS OF THE L-MYC ONCOGENE IN HEAD AND NECK-CANCER - RELATIONSHIP STUDY WITH SUSCEPTIBILITY AND DISEASE PROGRESSION

The L-myc DNA restriction fragment length polymorphism (RFLF), revealed by EcoRI digestion, has been evaluated in a case-control study including 161 head and neck cancer (HNSCC) patients and 160 normal healthy individuals with similar smoking and alcohol habits. No significant difference in the distribution of L-myc genotypes (LL, LS or SS) was found between the two populations implying thus no predisposition to head and neck tumour by either allele. There was no significant association between L-myc genotypes and the usual clinicopathological features such as T staging, differentiation status and lymph node involvement. Moreover, follow-up data from 154 patients was obtained and correlated with the L-myc pattern. No significant difference was observed in metastasis occurrence, multiple cancer incidence and survival data in the patients classified according to the L-myc genotypes; only a trend to preferentially develop metastasis in lung for patients with S allele was noted. In conclusion, our data shows that the L-myc typing does not contribute to HNSCC risk or prognosis assessment. A review of L-myc RFLP published studies shows contradictory results even on the same type of tumour and emphasizes the lacunae in understanding the biological role of L-myc for valid interpretation of L-myc allelic associations with cancer susceptibility or prognosis.

頭頚部に初発した５重悪性腫ようの１例

Multiple primary carcinomas were regarded as unusual. Improvements in diagno-stic techniques and treatment as well as extension of the average life span have increasedthe incidence of multiple cancers in recent years. Reports of triple or more cancers, however, are very scarce. In this paper, a very unusual case of quintuple malignancies is reported.The patient was a 64-year-old woman who had a squamous cell carcinoma of the buccalmucosa. During the following 9 years, breast carcinoma, squamous cell carcinoma of thegingiva of the mandible, and malignant lymphoma of the submandibular region developed. The patient died of heart failure during treatment for malignant lymphoma. Autopsyreveale the presence of adenocarcinoma of the colon.

口部咽頭癌に外科的療法，肝癌に肝動脈塞栓術を行った同時性重複癌の１例

The increasing incidence of multiple cancer in recent years has emphasized the importance of active and multimodal treatment for this disease. We have recently experienced a patient undergoing surgical treatment performed for oropharyngeal cancer and transcatheter arterial embolization for hepatic cancer in whom 2 years have passed postoperatively without any signs of recurrence or metastasis of either the oral or hepatic tumor. The case is described in this report.The patient was a 61-year-old male who had chronic hepatitis. On February 6, 1990, he initially presented at our clinic with the main complaints of redness of the oral mucosa and pain during eating. His oral lesion was definitivery diagnosed as squamous cell carcinoma of the left lateral oropharynx and tongue by incisional biopsy, and he was admitted to our hospital on February 20 of the same year. Concurrent hepatic cancer was suspected based on the results of in-depth preoperative general examinations. On May 16, laparoscopy was performed at the same time as surgical treatment for the oral cancer, and the hepatic lesion was diagnosed as primary hepatocellular carcinoma. On May 17, transcatheter arterial embolization was performed for hepatic cancer, and on July 14, he was discharged after postoperative adjuvant radiotherapy of the oral primary region and neck.

Correlation of L-myc RFLP with metastasis, prognosis and multiple cancer in lung-cancer patients.

For further study of the correlation of L-myc restriction-fragment-length polymorphism (RFLP) and metastasis of lung cancer to lymph nodes or other organs at the time of surgery, L-myc RFLP was analyzed in 252 Japanese lung-cancer patients. A close correlation between L-myc RFLP and metastasis was confirmed in this large number of patients (p = 0.01). The correlation was particularly pronounced in cases of adenocarcinoma and squamous-cell carcinoma. Poor prognosis (additional metastases after surgery) was observed in lung-cancer patients with L-S (identified as long and short bands produced with EcoRI) and S-S type L-myc RFLP. In addition, the death rate of lung-cancer patients with the L-S and S-S types was greater than that of those with the L-L type. Lung-cancer patients of the L-S and S-S types had almost 4 times higher incidence of multiple cancer in the lung, pharynx and other organs than those with the L-L type. Our results indicate that, in patients with lung cancer, genetic disposition with respect to the L-myc gene influences the extent of metastasis, the incidence of multiple cancers and prognosis.

Thyroid Cancer: Reports up to Date and a Review

Evidence to date from a number of studies, indicates that there is an increased incidence of thyroid cancer among A-bomb survivors, and that the incidence rises with increase of dose and is especially predominant in females exposed at younger ages. Although 45 years have elapsed since A-bomb exposure, there are still some questions about the development of thyroid cancer: 1) Is the incidence now decreasing? 2) What factors, other than radiation exposure, are involved? 3) What is the incidence of multiple cancer, including thyroid cancer? With these questions in mind, it is apparent that studies in this field must continue for some time to come.