The annual report to the nation on the status of cancer, 1973-1997, with a special section on colorectal cancer

Estrogen and gastrointestinal malignancy

The concept that E2 exerts an effect on the gastrointestinal tract is not new and its actions on intestinal mucosa have been investigated for at least three decades. An attempt to consolidate results of these investigations generates more questions than answers, thus suggesting that many unexplored avenues remain and that the full capabilities of this steroid hormone are far from understood. Evidence of its role in esophageal, gastric and gallbladder cancers is confusing and often equivocal. The most compelling evidence regards the protective role conferred by estrogen (or perhaps ERbeta) against the development and proliferation of colon cancer. Not only has the effect been described but also many mechanisms of action have been explored. It is likely that, along with surgery, chemotherapy and radiotherapy, hormonal manipulation will play an integral role in colon cancer management in the very near future.

Understanding barriers to cervical cancer screening among Hispanic women

OBJECTIVE

We investigated issues affecting Papanicolaou smear screening access, health services utilization, acculturation, social networking, and media venues most conducive to acquiring health information among Hispanics.

STUDY DESIGN

Self-identified Hispanics were surveyed. Participants were stratified based on age, time living in the United States, and Papanicolaou screening frequency.

RESULTS

Of 318 participants, Hispanics aged 30 years or older and living in the United States less than 5 years prefer speaking Spanish. Women with 5 or more lifetime Papanicolaou smears were 1.610 times more likely to have lived in the United States 5 or more years, 1.706 times more likely to speak a second language, and 1.712 times less likely to need a translator during their health care encounter.

CONCLUSION

Age and years living in the United States may be independent risk factors for participation in Papanicolaou screening programs. Social difficulties inherent to acculturation inform health behavior and translate to health disparity among Hispanics. Our results may help design federally funded and community-level programs.

Management of small polyps detected by screening CT colonography: patient and physician preferences

BACKGROUND

Management of small polyps found on computed tomography (CT) colonography is controversial and critical to both cancer outcomes and cost. Patient and physician behavior are influenced by personal beliefs and prior experience. Thus, we aimed to understand patient and physician preferences after finding polyps on CT colonography.

METHODS

Patients were given a validated handout and survey asking for their preference for evaluation of a "pea-sized" polyp found on CT colonography. By using an Internet survey, physicians were asked how they would manage a 5-mm, 8-mm, or 12-mm polyp, or three 5-mm polyps found by CT colonography in a hypothetical 52-year-old patient of average colorectal cancer risk. Survey reliability was assessed using Cronbach's coefficient alpha.

RESULTS

Of the 305 patient respondents, 95% wanted to know if the polyp found on CT colonography was precancerous, 86% stated they would request endoscopic evaluation, and 85% wanted polypectomy. Of the 277 primary care physicians, 71% would refer a 5-mm sigmoid polyp for endoscopy, 86% would refer an 8-mm polyp, 97% would refer a 12-mm polyp, and 91% would refer three 5-mm polyps. Of the 461 gastroenterologists, 83% would refer a 5-mm sigmoid polyp for endoscopy, 96% would refer an 8-mm polyp, 97% would refer a 12-mm polyp, and 93% would refer three 5-mm polyps. Overall, 75% of physicians indicated the fear of missing a precancerous lesion would prompt referral for colonoscopy.

CONCLUSION

Both patients and physicians overwhelmingly preferred to follow up small polyps identified by CT colonography with endoscopy, suggesting that population-based CT colonography screening programs in which polyps are not removed might require significant patient and physician education before implementation.

Survival of metastatic colorectal cancer patients treated with chemotherapy in Alberta (1995-2004)

Goals of work

Clinical trials have suggested that advances in chemotherapy significantly improve the survival of patients with metastatic colorectal cancer. Comparable evidence from clinical practice is scarce. This study aims to investigate the survival of patients with metastatic colorectal cancer treated with chemotherapy in Alberta, Canada.

Patients and methods

Trends of relative survival of patients diagnosed in 1994–2003 were assessed using Alberta Cancer Registry (ACR) data. The median overall survival (OS) of patients diagnosed in 2004 was determined by linking Cancer Registry data with Electronic Medical Records (EMR). Cox regression models were fitted to calculate the hazard ratio for patients treated with chemotherapy.

Results

The 2-year relative survival for patients with metastatic colorectal cancer who received chemotherapy increased significantly from 29% to 41% over the 10 years (1994–2003, p < 0.015). A 69% reduction in the risk of mortality was observed in the 168 patients who received chemotherapy compared to the 87 patients who did not, after adjusting for age, gender, and number of metastases. The median OS of patients who received chemotherapy was 17.5 months. This is comparable to the 18–20 months seen in recently published clinical trials, considering the patients in this study were from the real clinical practice, nearly half of them were older than 70, and many of them might have important co-morbidities.

Conclusions

The survival of patients diagnosed with metastatic colorectal cancer in Alberta has improved in recent years; this is most likely attributable in large part to the use of chemotherapy.

Monitoring of tumor promotion and progression in a mouse model of inflammation-induced colon cancer with magnetic resonance colonography

Early detection of precancerous tissue has significantly improved survival of most cancers including colorectal cancer (CRC). Animal models designed to study the early stages of cancer are valuable for identifying molecular events and response indicators that correlate with the onset of disease. The goal of this work was to investigate magnetic resonance (MR) colonography in a mouse model of CRC on a clinical MR imager. Mice treated with azoxymethane and dextran sulfate sodium were imaged by serial MR colonography (MRC) from initiation to euthanasia. Magnetic resonance colonography was obtained with both T1- and T2-weighted images after administration of a Fluorinert enema to remove residual luminal signal and intravenous contrast to enhance the colon wall. Individual tumor volumes were calculated and validated ex vivo. The Fluorinert enema provided a clear differentiation of the lumen of the colon from the mucosal lining. Inflammation was detected 3 days after dextran sulfate sodium exposure and subsided during the next week. Tumors as small as 1.2 mm(3) were detected and as early as 29 days after initiation. Individual tumor growths were followed over time, and tumor volumes were measured by MR imaging correlated with volumes measured ex vivo. The use of a Fluorinert enema during MRC in mice is critical for differentiating mural processes from intraluminal debris. Magnetic resonance colonography with Fluorinert enema and intravenous contrast enhancement will be useful in the study of the initial stages of colon cancer and will reduce the number of animals needed for preclinical trials of prevention or intervention.

A comprehensive comparative study on the characteristics of colorectal cancer chemotherapy

OBJECTIVE

Analyses were performed to assess whether the use of chemotherapeutic agents or regimens against colorectal cancer (CRC) differed among countries, especially the United States (USA), the European Union (EU) and Japan.

METHODS

The data source for this study was the IMS Health, Oncology Analyzer. We utilized data on the use of anticancer drugs and follow-up information for patients with CRC from April 2006 to March 2007, collected from the USA, the EU (G5: France, Germany, Italy, Spain and the UK) and Japan. A total of 102 502 patients were enrolled.

RESULTS

Wide differences were found in the actual regimens adopted by each region and nation. In other words, the concept of oncologist-related variability in chemotherapy for CRC was clearly seen. Factors such as a nation's historical characteristics and the healthcare policies of respective governments, including drug approval and cost-effectiveness, also appeared to have roles. However, comparisons of 5-year relative survival rates from population-based cancer registries in the USA, the EU and Japan showed that survival rates for CRC in the three regions did not differ widely, despite differences in the actual use of medical therapy. This may suggest that regional usage trends for anticancer regimens were optimal, although the application of chemotherapy was not the intentional standardization.

CONCLUSIONS

Global information exchanges regarding oncologist-related factors along with global evidence could result in patient survival being prolonged by the establishment of intentional standardized treatments suited for regional characteristics.

Incidence and anatomic presentation of cutaneous malignant melanoma in central Canada during a 50-year period: 1956 to 2005

BACKGROUND

Incidence rates of cutaneous malignant melanoma (CMM) have increased worldwide. Long-term studies examining rates and anatomic site-specific incidence on a population-based level are infrequent.

OBJECTIVE

We sought to examine the historical changes in the incidence and anatomic site presentation of CMM during a 50-year period in Manitoba, Canada.

METHODS

Using population-based data, all first diagnoses of CMM reported between 1956 and 2005 were identified. Age-specific rates, age-standardized incidence rates, and anatomic sites were recorded.

RESULTS

Incidence rates of CMM slowed for each sex beginning in 1981 for female patients and 1992 for male patients. Annual percent change revealed decreasing rates among male patients younger than 40 years (1992-2005: -5.3% [P = .03]) and female patients younger than 40 years (1987-2005: -1.8% [P = .15]). Similarly, middle-aged individuals (age 40-59 years) also had diminished annual percent change (men 1992-2005: 0.6% [P = .65]; women 1983-2005: -0.3% [P = .68]). The annual percent change for older men and women (60-79 and > or =80 years) continued to increase. Anatomic site-specific analyses revealed that the trunk was the most frequent site of CMM for young male patients (<60 years) whereas the lower extremities were the most common among young female patients (<60 years). Incidence rates for each site, however, are slowing. Among those aged 60 years and older, the rates for each anatomic site increased.

LIMITATIONS

Determining changes in tumor thickness would have been useful in determining whether the nature of tumors have changed over time; however, this is not recorded in our registry.

CONCLUSION

The rates of CMM are slowing; however, this change is confined to younger individuals. Anatomic site-specific CMMs are changing; rates among older individuals continue to increase for both sexes.

Cancer screening practices among physicians serving Chinese immigrants

Chinese immigrants in the United States are broadly affected by cancer health disparities. We examined the cancer screening attitudes and practices of physicians serving Chinese immigrants in the New York City (NYC) area by mailing a cancer screening survey, based on current guidelines, to a random sample of physicians serving this population. Fifty three physicians (44%) completed the survey. Seventy-two percent reported following the guidelines for breast cancer, 35% for cervical cancer screening, and 45% for all colorectal cancer screening tests. Sixty-eight percent of physicians were satisfied with their current rates of cancer screening with their Chinese immigrant patient population. Physicians serving the Chinese community in NYC follow cancer screening guidelines inadequately. Cancer screening rates in this population could likely be increased by interventions that target physicians and improve awareness of guidelines and recommended best practices.

Management of familial melanoma and nonmelanoma skin cancer syndromes

The clinical manifestations of hereditary skin cancer syndromes depend upon the interplay between environmental and genetic factors. Familial melanoma occurs in the setting of hereditary susceptibility, with a complex phenotype of early age of onset, multiple atypical moles, multiple primary melanomas, multiple melanomas in the family, and in some instances pancreatic cancer. Identification of individuals who may have a hereditary susceptibility for the development of melanoma is essential to provide an opportunity for primary prevention, and to target high-risk groups for early diagnosis and treatment. Consequently, the surgeon as one of the primary caregivers should be familiar with hereditary skin cancer syndromes and their pathogenesis, diagnosis, management, and surveillance recommendations. This article discusses a practical approach for some of the issues likely encountered by the surgeon in the management of familial melanoma and non-melanoma skin cancer.

Inflammation-associated serum and colon markers as indicators of dietary attenuation of colon carcinogenesis in ob/ob mice

Although inflammatory cytokines and obesity-associated serum proteins have been reported as biomarkers of colorectal adenoma risk in humans, little is known of biomarkers of response to interventions that attenuate tumorigenesis. Dietary navy beans and their fractions attenuate colon carcinogenesis in carcinogen-induced genetically obese mice. We hypothesized that this attenuation would be associated with changes in inflammatory cytokines and obesity-related serum proteins that may serve as measures of efficacy. ob/ob mice (n = 160) were injected with the carcinogen azoxymethane (AOM) to induce colon cancer and randomly placed on one of four diets (control, whole navy bean, bean residue fraction, or bean extract fraction) for 26 to 28 wk. Serum was analyzed for 14 inflammation- or obesity-related proteins, and colon RNA was analyzed for expression of 84 inflammation-associated genes. Six of 14 serum proteins were increased [i.e., interleukin (IL)-4, IL-5, IL-6, IL-10, IFN gamma, granulocyte macrophage colony-stimulating factor] in hyperplastic/dysplastic stages of colon carcinogenesis. Bean-fed mice had significantly higher monocyte chemoattractant protein-1 and lower IL-6 levels in serum. In colon mucosa, 55 of 84 inflammation-associated genes differed between AOM-induced and noninduced mice. Of the 55 AOM-induced genes, 5 were counteracted by bean diets, including IL-6 whose increase in expression levels was attenuated by bean diets in AOM-induced mice. In summary, IL-6 emerged as a serum protein that was increased in hyperplastic/dysplastic stages of colon carcinogenesis, but attenuated with bean-based diet in serum and colon mucosa. Changes in a subset of inflammation-associated serum proteins and colon gene expression may serve as response indicators of dietary attenuation of colon carcinogenesis.

Small-molecule antagonists for CXCR2 and CXCR1 inhibit human melanoma growth by decreasing tumor cell proliferation, survival, and angiogenesis

PURPOSE

Melanoma, the most aggressive form of skin cancer, accounts for 75% of all skin cancer-related deaths and current therapeutic strategies are not effective in advanced disease. In the current study, we have investigated the efficacy of orally active small-molecule antagonist targeting CXCR2/CXCR1.

EXPERIMENTAL DESIGN

Human A375SM melanoma cells were treated with SCH-479833 or SCH-527123, and their effect on proliferation, motility, and invasion was evaluated in vitro. We examined the downstream signaling events in the cells following treatment with antagonists. For in vivo studies, A375SM cells were implanted subcutaneously into athymic nude mice followed by administration of SCH-479833, SCH-527123, or hydroxypropyl-beta-cyclodextrin (20%) orally for 21 days and their effect on tumor growth and angiogenesis was evaluated.

RESULTS

Our data show that SCH-479833 or SCH-527123 inhibited the melanoma cell proliferation, chemotaxis, and invasive potential in vitro. Treatment of melanoma cells with SCH-479833 or SCH-527123 also inhibited tumor growth. Histologic and histochemical analyses showed significant (P < 0.05) decreases in tumor cell proliferation and microvessel density in tumors. Moreover, we observed a significant increase in melanoma cell apoptosis in SCH-479833- or SCH-527123-treated animals compared with controls.

CONCLUSION

Together, these studies show that selectively targeting CXCR2/CXCR1 with orally active small-molecule inhibitors is a promising therapeutic approach for inhibiting melanoma growth and angiogenesis.

Melanoma biology and the promise of zebrafish

Advantageous organismal and technical attributes of the zebrafish are being increasingly applied to study cancer biology. Along with other tumor models, zebrafish that develop melanomas have been generated. In both genetics and phenotype, zebrafish melanomas are strikingly similar to their human counterparts. For this reason, studies in the zebrafish are poised to make significant contributions to melanoma biology. In this review, we summarize important features of human melanoma and discuss how the zebrafish can be used to address many questions that remain unanswered about this devastating disease.

A Joinpoint regression analysis of long-term trends in cancer mortality in Japan (1958-2004)

Cancer is one of the major targets of disease control programs in Japan. A Joinpoint regression model was used to analyze the long-term trends of mortality related to overall cancer and the 15 most common cancers based on published data from the National Vital Statistics of Japan between 1958 and 2004. Since 1996, a decline has been seen in overall cancer for both sexes in Japan. Most of the common sites, including cancers of the stomach, colon, liver, gallbladder and lung and leukemia in both sexes, cancer of esophagus in men and rectal and ovarian cancers in women showed a decreasing trend, and cancers of the rectum, pancreas, prostate and urinary bladder and malignant lymphoma in men and cancers of the esophagus and uterus in women leveled off during the most recent period. However, an increasing trend was confirmed for cancers of the pancreas, breast and urinary bladder and malignant lymphoma in women. An effective cancer control program including prevention, early detection and treatment should be implemented to further reduce the cancer mortality, particularly for cancer sites that show higher mortality rates or increasing trends.

Outcome of right colectomy for cancer in octogenarians

BACKGROUND

Colorectal cancer is one of the commonest malignancies in the elderly and, as such, is a major cause of morbidity and mortality. There is no consensus yet if age itself is a risk factor for adverse outcome after colectomy. The aims of the study were to evaluate the impact of age on operative results of right colectomy for cancer and to define factors that influence the postoperative mortality in octogenarians.

METHODS

Data of all patients who underwent right colectomy for colon cancer between January 2001 and December 2006 were collected retrospectively. Patients were divided into two groups: those who were 80 years and older and those who were less than 80 years old. Analysis included patients' demographics, comorbidities, American Society of Anesthesiologists class, functional status, mode of presentation, stage of disease, length of hospital stay, postoperative morbidity, and mortality.

RESULTS

A total of 124 consecutive patients with right colon cancer were operated. Control group included 84 patients less than 80 year old. Study group included 40 patients 80 years or older. In Cox multivariate regression analysis, poor functional status and emergent surgery were independent factors for postoperative mortality.

CONCLUSIONS

There was no significant difference in the outcome of elective right colectomy between elderly patients and their younger counterparts. Operative mortality of emergency surgery was significantly higher in octogenarians. Emergent setting and poor functional status are major risk factors for postoperative mortality.

Annual report to the nation on the status of cancer, 1975-2005, featuring trends in lung cancer, tobacco use, and tobacco control

BACKGROUND

The American Cancer Society, the Centers for Disease Control and Prevention (CDC), the National Cancer Institute (NCI), and the North American Association of Central Cancer Registries (NAACCR) collaborate annually to provide updated information on cancer occurrence and trends in the United States. This year's report includes trends in lung cancer incidence and death rates, tobacco use, and tobacco control by state of residence.

METHODS

Information on invasive cancers was obtained from the NCI, CDC, and NAACCR and information on mortality from the CDC's National Center for Health Statistics. Annual percentage changes in the age-standardized incidence and death rates (2000 US population standard) for all cancers combined and for the top 15 cancers were estimated by joinpoint analysis of long-term (1975-2005) trends and by least squares linear regression of short-term (1996-2005) trends. All statistical tests were two-sided.

RESULTS

Both incidence and death rates from all cancers combined decreased statistically significantly (P < .05) in men and women overall and in most racial and ethnic populations. These decreases were driven largely by declines in both incidence and death rates for the three most common cancers in men (lung, colorectum, and prostate) and for two of the three leading cancers in women (breast and colorectum), combined with a leveling off of lung cancer death rates in women. Although the national trend in female lung cancer death rates has stabilized since 2003, after increasing for several decades, there is prominent state and regional variation. Lung cancer incidence and/or death rates among women increased in 18 states, 16 of them in the South or Midwest, where, on average, the prevalence of smoking was higher and the annual percentage decrease in current smoking among adult women was lower than in the West and Northeast. California was the only state with decreasing lung cancer incidence and death rates in women.

CONCLUSIONS

Although the decrease in overall cancer incidence and death rates is encouraging, large state and regional differences in lung cancer trends among women underscore the need to maintain and strengthen many state tobacco control programs.

Clinical management of small (6- to 9-mm) polyps detected at screening CT colonography: a cost-effectiveness analysis

OBJECTIVE

The primary aim of this model analysis was to compare the clinical and economic impacts of immediate polypectomy versus 3-year CT colonography (CTC) surveillance for small (6- to 9-mm) polyps detected at CTC screening.

MATERIALS AND METHODS

A decision analysis model was constructed incorporating the expected advanced neoplasia prevalence, frequency of measurable growth, colorectal cancer (CRC) prevalence and risk, CTC performance, and costs related to CRC screening and treatment. CRC risk was assumed to be independent of advanced adenoma size, which intentionally overestimates the risk related to small polyps. Clinical effectiveness and costs for 3-year CTC surveillance versus immediate colonoscopic polypectomy were compared for a concentrated cohort of patients with 6- to 9-mm polyps. For the CTC surveillance strategy, only cases with measurable growth (> or = 1 mm) at follow-up CTC were referred for polypectomy.

RESULTS

Without any intervention, the estimated 5-year CRC death rate from 6- to 9-mm polyps in this concentrated cohort was 0.08%, which is a sevenfold decrease over the 0.56% CRC risk for the general unselected screening population. The death rate was further reduced to 0.03% with the CTC surveillance strategy and to 0.02% with immediate colonoscopy referral. However, for each additional cancer-related death prevented with immediate polypectomy versus CTC follow-up, 9,977 colonoscopy referrals would be needed, resulting in 10 additional perforations and an incremental cost-effectiveness ratio of $372,853.

CONCLUSION

For patients with small (6- to 9-mm) polyps detected at CTC screening, the exclusion of large polyps (> or = 10 mm) already confers a very low risk of CRC. The high costs, additional complications, and relatively low incremental yield associated with immediate polypectomy of 6- to 9-mm polyps support the practice of 3-year CTC surveillance, which allows for selective noninvasive identification of small polyps at risk.

Transcriptional analysis of estrogen receptor alpha variant mRNAs in colorectal cancers and their matched normal colorectal tissues

Estrogen is involved in suppression of colorectal cancer development and exerts its function via estrogen receptors alpha, beta and their splicing variants. Whether the recently indentified ER-alpha splicing variants, ER-alpha36 and ER-alpha46, play a role in colorectal cancer development is unknown. In this study, we quantified the mRNA copy numbers of wild type ER-alpha (ER-alpha66), ER-alpha46 and ER-alpha36 in 35 colorectal cancers and their matched normal colorectal tissues by quantitative real-time PCR assay, and correlated their mRNA levels with the clinicopathological properties of the tumors. We found that ER-alpha66, ER-alpha46 and ER-alpha36 mRNAs were coexpressed in all colorectal cancers and their matched normal tissues. The decreased mRNA levels of ER-alpha36 and ER-alpha46 whereas no difference of ER-alpha66 mRNA was observed in colorectal cancers compared to their matched normal tissues. Moreover, change in the expression of ER-alpha36 mRNA level was correlated with Dukes' stage of the tumor and the lymph node metastasis. ER-alpha36 mRNA was decreased significantly in Dukes' C+D compared to Dukes' A+B stage tumors (P=0.017), and the expression of ER-alpha36 mRNA in N(1)/N(2) was lower than that in N(0) lymph node metastasis (P=0.049). So ER-alpha36 and ER-alpha46 might be implicated in the development and progression of colorectal cancers.

Head and neck cancer: an evolving treatment paradigm

Since the inception of this journal in 1948, the understanding of etiologic factors that contribute to and the treatment of head and neck cancer has evolved dramatically. Advances in surgery, radiation therapy, and chemotherapy have improved locoregional control, survival, and quality of life. The outcomes of these treatment modalities have shifted the focus of curative efforts from radical ablation to preservation and restoration of function. This evolution has been documented in the pages of Cancer for the past 6 decades. This review focuses on the evolution of treatment approaches for head and neck cancer and future directions while recognizing the historic contributions recorded within this journal.

Efficacy of chromoendoscopy with indigocarmine for the detection of ascending colon and cecum lesions

OBJECTIVE

Previous data suggest that routine chromoendoscopy may increase detection rates of diminutive or flat lesions. The aim of this study was to evaluate the usefulness of chromoendoscopy in the ascending colon and cecum, where the incidence of diminutive or flat lesions is high.

MATERIAL AND METHODS

Between June 2006 and September 2006, a total of 316 consecutive patients were prospectively enrolled in this study. The patients were randomly divided into two groups (control group: 158 patients, chromoendoscopy group: 158 patients). If the quality of bowel preparation was poor or cecal intubation was not achieved, the patient was excluded from the study. In the control group, the ascending colon and cecum were observed twice without chromoendoscopy. In the chromoendoscopy group, the cecum and ascending colon were reinspected following staining with indigocarmine solution after conventional examination of the cecum and ascending colon. Finally, a total of 151 and 149 patients were enrolled in the control and chromoendoscopy groups, respectively.

RESULTS

The chromoendoscopy group differed significantly from the control group in the number of additionally detected polyps (control: 14 versus chromoendoscopy: 62, p<0.001) and in the number of patients with additionally detected polyps (control: 12 versus chromoendoscopy: 50, p<0.001). Multivariate analysis revealed that detection of polyps after indigocarmine spraying was independently associated with a high body mass index and older age (p = 0.045 and p = 0.006, respectively).

CONCLUSIONS

With chromoendoscopy using indigocarmine, more polyps can be detected in the ascending colon and cecum as compared with using conventional colonoscopy.

Epidemiology and management options for colorectal cancer in children

Colorectal carcinoma (CRC), although primarily a disease of adulthood, accounts for 2% of malignancies in adolescents and has been reported in children as young as 9 months of age. Our knowledge of CRC in pediatrics is based on a handful of case series and case reports. Apart from one small clinical trial, there has been a lack of prospective clinical studies in this age group. Based on these published reports, most CRC in children is sporadic, but it can also arise in the setting of predisposing conditions, such as gastrointestinal polyposis syndromes, nonpolyposis familial cancer syndromes, and inflammatory bowel disease. Despite some similarities to adult disease, CRC in childhood may be intrinsically different biologically, because it differs from adult-onset CRC in several respects. Childhood CRC tends to be diagnosed at an advanced stage, is largely of mucinous histology, and (probably because of these features) tends to have a poorer outcome. As a result of its rarity in children and the lack of prospective pediatric studies, recommendations for therapy are primarily extrapolated from adult clinical trials. A review of pediatric case series in the English literature emphasizes the prognostic significance of stage of disease, as well as extent of surgical resection. As in adults, early detection is critical in an effort to capture the disease at less advanced stages. Complete surgical resection with aggressive lymph node dissection is essential for cure, and neoadjuvant chemotherapy may be used in an effort to render unresectable lesions resectable. Active agents in adults with CRC include fluorouracil, folinic acid (leucovorin), oxaliplatin, and irinotecan. Furthermore, newer targeted therapeutic agents, such as bevacizumab and cetuximab, have added additional efficacy to the standard chemotherapy backbone. Collaborative multi-institutional pediatric clinical trials are needed to evaluate the prognosis, optimal treatment response, and the basic biology of childhood onset CRC.

Diverticulosis and colorectal cancer: between lights and shadows

The prevalence of diverticulosis and colorectal cancer (CRC) is markedly increased in the last century. Both diseases are highly frequent in Western countries and in aged people. Western diet--low in fiber and rich in dietary fat--has been largely regarded to play a major role in the pathogenesis of both conditions. A causal relationship between diverticulosis and CRC has been suggested in different studies. Epidemiologic series found a more frequent rectosigmoid localization of neoplastic lesions (advanced adenoma and CRC) in patients with diverticulosis as compared with controls, particularly in those with a previous diverticulitis episode or with an extensive disease. However, data are still controversial, with other studies failing to confirm this observation. Such discrepancy could be referred to the highly heterogeneous study design and setting in the different epidemiologic series. Pathologic studies showed that either macroscopic and microscopic chronic inflammation--which is regarded as risk factor for CRC development--is present in the colonic mucosa of some patients with diverticula. Moreover, alterations in the extracellular matrix, also involved in colorectal carcinogenesis, have been depicted in diverticulosis. In addition, an upward shifting of cell proliferation occurs in diverticular mucosa, and in nondiverticular patients with advanced adenomas. Finally, aberrant crypt foci--which are considered potential markers of CRC risk in ulcerative colitis--have been detected in colonic mucosa of patients with diverticulosis. Despite this substantial amount of evidence, however, the available data are not yet strong enough to suggest a more aggressive CRC prevention in diverticular as compared with nondiverticular subjects.

"Self and parent-assessed skin cancer risk factors in school-age children"

OBJECTIVE

To evaluate sunburn, sun sensitivity factors and sun protection behavior in school-age children.

METHODS

2002 to 2004 survey of 2942 children in primary schools of Valencia, Spain, and their parents, using a self-administered questionnaire filled by the children with the help of their parents.

RESULTS

Having a fair skin (OR: 2.05; 95% CI: 1.38-3.04), light coloured eyes (OR: 1.38; 95% CI: 1.12-1.68), freckles (OR: 1.32; 95% CI:1.12-1.56), and older age (OR: 2.34; 95% CI:1.96-2.80) were associated with occurrence of sunburns. Hair color, gender, use of sunscreens, wearing T-shirts and sunglasses were not. Wearing hats (OR: 0.64; 95% CI: 0.54-0.75) was inversely associated. Parents were significantly more inclined to protect younger and fair-skinned children with sunscreen and T-shirts.

CONCLUSIONS

As expected, phenotype is related to sunburns and appears to influence parent's sun protection behaviours.

Treatment and survival in a population-based sample of patients diagnosed with gastroesophageal adenocarcinoma

AIM

To examine the extent of use of specific therapies in clinical practice, and their relationship to therapies validated in clinical trials.

METHODS

The US National Cancer Institutes' Patterns of Care study was used to examine therapies and survival of patients diagnosed in 2001 with histologically-confirmed gastroesophageal adenocarcinoma (n = 1356). The study re-abstracted data and verified therapy with treating physicians for a population-based stratified random sample.

RESULTS

Approximately 62% of patients had stomach adenocarcinoma (SAC), while 22% had gastric-cardia adenocarcinoma (GCA), and 16% lower esophageal adenocarcinoma (EAC). Stage IV/unstaged esophageal cancer patients were most likely and stage I-III stomach cancer patients least likely to receive chemotherapy as all or part of their therapy; gastric-cardia patients received chemotherapy at a rate between these two. In multivariable analysis by anatomic site, patients 70 years and older were significantly less likely than younger patients to receive chemotherapy alone or chemoradiation for all three anatomic sites. Among esophageal and stomach cancer patients, receipt of chemotherapy was associated with lower mortality; but no association was found among gastric-cardia patients.

CONCLUSION

This study highlights the relatively low use of clinical trials-validated anti-cancer therapies in community practice. Use of chemotherapy-based treatment was associated with lower mortality, dependent on anatomic site. Findings suggest that physicians treat lower esophageal and SAC as two distinct entities, while gastric-cardia patients receive a mix of the treatment strategies employed for the two other sites.

Variations in practice guideline adherence for abnormal cervical cytology in a county healthcare system

BACKGROUND

Reduction in cervical cancer incidence and mortality is not only dependant on promoting cervical cancer screening but also on providing appropriate follow-up and treatment of abnormal cervical cytology.

OBJECTIVES

The objective of this study was to determine variations in guideline adherence for women requiring abnormal cervical cytology follow-up.

SUBJECTS

Subjects of the study are women 18 years or older with an abnormal Pap test in 2000 within a large county healthcare system (n = 8,571).

MEASUREMENTS

Guideline adherence was determined by the presence or absence of the appropriate follow-up procedure within an acceptable time interval for each degree of cytological abnormality. Patients with no follow-up studies were deemed to be lost to follow-up.

RESULTS

Of study subjects, 18.5% were lost to follow-up care. Of the remaining 6,987 women, 60.3% received optimal care, 9.4% received suboptimal care, and 30.3% received poor care. Follow-up rates were higher for patients with higher degree of cytological abnormality (OR, 1.29, 95% CI, 1.17-1.42), older patients (OR, 1.03, 95% CI, 1.02-1.030) and those receiving the index Pap test at a larger healthcare facility (OR, 1.13; 95% CI, 1.01-1.27). Receiving optimal care was positively correlated with higher degree of cytological abnormality (p < .0001) and larger facility size (p = .002). Regional variations in care demonstrated the largest cluster having the lowest lost to follow-up rate and the most optimal care.

CONCLUSIONS

A significant number of women with abnormal cervical cytology are receiving less than optimal care. Further studies are required to determine the specific healthcare delivery practices that need to be targeted to improve guideline adherence for follow-up of abnormal cytology.

Oestrogen and the colon: potential mechanisms for cancer prevention

The role of oestrogen in oncogenesis has been examined extensively, especially in the context of breast cancer, and receptor modulators are an integral part of targeted treatment in this disease. The role of oestrogen signalling in colonic carcinoma is poorly understood. Men are more susceptible than women to colon cancer. Furthermore, hormone-replacement therapy affords an additive protective effect for postmenopausal women, and when these women do develop cancer, they typically have less aggressive disease. The discovery of a second oestrogen receptor (ERbeta) and its over expression in healthy human colon coupled with reduced expression in colon cancer suggests that this receptor might be involved. The underlying mechanism, however, remains largely unknown. In this Review, we discuss the various hypotheses presented in the published literature. We examine the cellular and molecular mechanisms through which oestrogen is purported to exert its protective influence, and we review the evidence available to support these claims.

Long-term results of laparoscopic colorectal cancer resection

BACKGROUND

Although minimally invasive surgery has been accepted for a variety of disorders, laparoscopic resection of colorectal cancer is performed by few. Concern about oncological radicality and long term outcome has limited the adoption of laparoscopic surgery for colorectal cancer.

OBJECTIVES

To determine long-term outcome after laparoscopically-assisted versus open surgery for non-metastasised colorectal cancer.

SEARCH STRATEGY

The Cochrane library, EMBASE, Pub med and Cancer Lit were searched for published and unpublished randomised controlled trials.

SELECTION CRITERIA

Randomised clinical trials comparing laparoscopically-assisted and open surgery for non-metastasised colorectal cancer were included. Studies that did not report any long-term outcomes were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the studies and extracted data. RevMan 4.2 was used for statistical analysis.

MAIN RESULTS

Thirty-three randomised clinical trials (RCT) comparing laparoscopically-assisted versus open surgery for colorectal cancer were identified. Twelve of these trials, involving 3346 patients, reported long-term outcome and were included in the current analysis. No significant differences in the occurrence of incisional hernia, reoperations for incisional hernia or reoperations for adhesions were found between laparoscopically assisted and open surgery (2 RCT, 474 pts, 7.9% vs 10.9%;P = 0.32 and 2 RCT, 474 pts, 4.0% vs 2.8%; P = 0.42 and 1 RCT, 391 pts, 1.1% vs 2.5%;P = 0.30, respectively). Rates of recurrence at the site of the primary tumor were similar (colon cancer: 4 RCT, 938 pts, 5.2% vs 5.6%; OR (fixed) 0.84 (95% CI 0.47 to 1.52)(P = 0.57); rectal cancer: 4 RCT, 714 pts, 7.2% vs 7.7%; OR (fixed) 0.81 (95% CI 0.45 to 1.43) (P = 0.46). No differences in the occurrence of port-site/wound recurrences were observed (P=0.16). Similar cancer-related mortality was found after laparoscopic surgery compared to open surgery ( colon cancer: 5 RCT, 1575 pts, 14.6% vs 16.4%; OR (fixed) 0.80 (95% CI 0.61 to 1.06) (P=0.15); rectal cancer: 3 RCT, 578 pts, 9.2% vs 10.0%; OR (fixed) 0.66 (95% CI 0.37 to 1.19) (P=0.16). Four studies were included in the meta-analyses on hazard ratios for tumour recurrence in laparoscopic colorectal cancer surgery. No significant difference in recurrence rate was observed between laparoscopic and open surgery (hazard ratio for tumour recurrence in the laparoscopic group 0.92; 95% CI 0.76-1.13). No significant difference in tumour recurrence between laparoscopic and open surgery for colon cancer was observed (hazard ratio for tumour recurrence in the laparoscopic group 0.86; 95% CI 0.70-1.08).

AUTHORS' CONCLUSIONS

Laparoscopic resection of carcinoma of the colon is associated with a long term outcome no different from that of open colectomy. Further studies are required to determine whether the incidence of incisional hernias and adhesions is affected by method of approach. Laparoscopic surgery for cancer of the upper rectum is feasible, but more randomised trials need to be conducted to assess long term outcome.

Long-term results of laparoscopic colorectal cancer resection

BACKGROUND

Although minimally invasive surgery has been accepted for a variety of disorders, laparoscopic resection of colorectal cancer is performed by few. Concern about oncological radicality and long term outcome has limited the adoption of laparoscopic surgery for colorectal cancer.

OBJECTIVES

To determine long-term outcome after laparoscopically-assisted versus open surgery for non-metastasised colorectal cancer.

SEARCH STRATEGY

The Cochrane library, EMBASE, Pub med and Cancer Lit were searched for published and unpublished randomised controlled trials.

SELECTION CRITERIA

Randomised clinical trials comparing laparoscopically-assisted and open surgery for non-metastasised colorectal cancer were included. Studies that did not report any long-term outcomes were excluded.

DATA COLLECTION AND ANALYSIS

Two reviewers independently assessed the studies and extracted data. RevMan 4.2 was used for statistical analysis.

MAIN RESULTS

Thirty-three randomised clinical trials (RCT) comparing laparoscopically-assisted versus open surgery for colorectal cancer were identified. Twelve of these trials, involving 3346 patients, reported long-term outcome and were included in the current analysis. No significant differences in the occurrence of incisional hernia, reoperations for incisional hernia or reoperations for adhesions were found between laparoscopically assisted and open surgery (2 RCT, 474 pts, 7.9% vs 10.9%;P = 0.32 and 2 RCT, 474 pts, 4.0% vs 2.8%; P = 0.42 and 1 RCT, 391 pts, 1.1% vs 2.5%;P = 0.30, respectively). Rates of recurrence at the site of the primary tumor were similar (colon cancer: 4 RCT, 938 pts, 5.2% vs 5.6%; OR (fixed) 0.84 (95% CI 0.47 to 1.52)(P = 0.57); rectal cancer: 4 RCT, 714 pts, 7.2% vs 7.7%; OR (fixed) 0.81 (95% CI 0.45 to 1.43) (P = 0.46). No differences in the occurrence of port-site/wound recurrences were observed (P=0.16). Similar cancer-related mortality was found after laparoscopic surgery compared to open surgery ( colon cancer: 5 RCT, 1575 pts, 14.6% vs 16.4%; OR (fixed) 0.80 (95% CI 0.61 to 1.06) (P=0.15); rectal cancer: 3 RCT, 578 pts, 9.2% vs 10.0%; OR (fixed) 0.66 (95% CI 0.37 to 1.19) (P=0.16). Four studies were included in the meta-analyses on hazard ratios for tumour recurrence in laparoscopic colorectal cancer surgery. No significant difference in recurrence rate was observed between laparoscopic and open surgery (hazard ratio for tumour recurrence in the laparoscopic group 0.92; 95% CI 0.76-1.13). No significant difference in tumour recurrence between laparoscopic and open surgery for colon cancer was observed (hazard ratio for tumour recurrence in the laparoscopic group 0.86; 95% CI 0.70-1.08).

AUTHORS' CONCLUSIONS

Laparoscopic resection of carcinoma of the colon is associated with a long term outcome no different from that of open colectomy. Further studies are required to determine whether the incidence of incisional hernias and adhesions is affected by method of approach. Laparoscopic surgery for cancer of the upper rectum is feasible, but more randomised trials need to be conducted to assess long term outcome.

A role for the androgen-receptor in clinically localized and advanced prostate cancer

Earlier studies of androgen-receptor (AR) expression using frozen prostate tissue, and later studies using archived specimens, produced the consensus that ligand-stabilized AR is nuclear, AR expression is similar in benign epithelia and stroma, AR expression is greater in secretory epithelia than basal cells, and AR expression is more variable in prostate cancer (CaP) than in benign prostatic hyperplasia (BPH). Accurate measurement of AR expression remains technically challenging but necessary to evaluate the relevance of AR to clinical CaP. Recent studies demonstrated that AR expression in epithelia and stroma may be prognostic in clinically localized CaP, and AR expression may play a role in racial differences in CaP mortality and predict response to androgen deprivation therapy. High levels of AR and AR-regulated gene expression indicate a central role for AR in growth regulation of castration-recurrent CaP. New treatments for the lethal phenotype of CaP require better understanding of AR transactivation during androgen deprivation therapy.

African-American and Caucasian disparities in colorectal cancer mortality and survival by data source: an epidemiologic review

Over the past four decades in the United States, there has been a divergent trend in mortality rates between African-Americans and Caucasians with colorectal cancer (CRC). Rates among Caucasians have been steadily declining, whereas rates among African-Americans have only started a gradual decline in recent years. We reviewed epidemiologic studies of CRC racial disparities between African-Americans and Caucasians, including studies from SEER and population-based cancer registries, Veterans Affairs (VA) databases, healthcare coverage databases, and university and other medical center data sources. Elevated overall and stage-specific risks of CRC mortality and shorter survival for African-Americans compared with Caucasians were reported across all data sources. The magnitude of racial disparities varied across study groups, with the strongest associations observed in university and non-VA hospital-based medical center studies, while an attenuated discrepancy was found in VA database studies. An advanced stage of disease at the time of diagnosis among African-Americans is a major contributing factor to the racial disparity in survival. Several studies, however, have shown that an increased risk of CRC death among African-Americans remains even after controlling for tumor stage at diagnosis, socioeconomic factors, and co-morbidity. Despite advances in treatment, improvements in the standard of care, and increased screening options, racial differences persist in CRC mortality and survival. Therefore, continued research efforts are necessary to disentangle the clinical, social, biological, and environmental factors that constitute the racial disparity. In addition, results across data sources should be considered when evaluating racial differences in cancer outcomes.

Gender differences in skin: a review of the literature

BACKGROUND

There has been increasing interest in studying gender differences in skin to learn more about disease pathogenesis and to discover more effective treatments. Recent advances have been made in our understanding of these differences in skin histology, physiology, and immunology, and they have implications for diseases such as acne, eczema, alopecia, skin cancer, wound healing, and rheumatologic diseases with skin manifestations.

OBJECTIVE

This article reviews advances in our understanding of gender differences in skin.

METHODS

Using the PubMed database, broad searches for topics, with search terms such as gender differences in skin and sex differences in skin, as well as targeted searches for gender differences in specific dermatologic diseases, such as gender differences in melanoma, were performed. Additional articles were identified from cited references. Articles reporting gender differences in the following areas were reviewed: acne, skin cancer, wound healing, immunology, hair/alopecia, histology and skin physiology, disease-specific gender differences, and psychological responses to disease burden.

RESULTS

A recurring theme encountered in many of the articles reviewed referred to a delicate balance between normal and pathogenic conditions. This theme is highlighted by the complex interplay between estrogens and androgens in men and women, and how changes and adaptations with aging affect the disease process. Sex steroids modulate epidermal and dermal thickness as well as immune system function, and changes in these hormonal levels with aging and/or disease processes alter skin surface pH, quality of wound healing, and propensity to develop autoimmune disease, thereby significantly influencing potential for infection and other disease states. Gender differences in alopecia, acne, and skin cancers also distinguish hormonal interactions as a major target for which more research is needed to translate current findings to clinically significant diagnostic and therapeutic applications.

CONCLUSIONS

The published findings on gender differences in skin yielded many advances in our understanding of cancer, immunology, psychology, skin histology, and specific dermatologic diseases. These advances will enable us to learn more about disease pathogenesis, with the goal of offering better treatments. Although gender differences can help us to individually tailor clinical management of disease processes, it is important to remember that a patient's sex should not radically alter diagnostic or therapeutic efforts until clinically significant differences between males and females arise from these findings. Because many of the results reviewed did not originate from randomized controlled clinical trials, it is difficult to generalize the data to the general population. However, the pressing need for additional research in these areas becomes exceedingly clear, and there is already a strong foundation on which to base future investigations.

Changes in the incidence and outcome for early acute kidney injury in a cohort of Australian intensive care units

INTRODUCTION

There is limited information on whether the incidence of acute kidney injury (AKI) in critically ill patients has changed over time and there is controversy on whether its outcome has improved.

METHODS

We interrogated the Australian New Zealand Intensive Care Society Adult Patient Database to obtain data on all adult admissions to 20 Australian intensive care units (ICUs) for >or= 24 hours from 1 January 1996 to 31 December 2005. Trends in incidence and mortality for ICU admissions associated with early AKI were assessed.

RESULTS

There were 91,254 patient admissions to the 20 study ICUs, with 4,754 cases of AKI, for an estimated crude cumulative incidence of 5.2% (95% confidence interval, 5.1 to 5.4). The incidence of AKI increased during the study period, with an estimated annual increment of 2.8% (95% confidence interval, 1.0 to 5.6, P = 0.04). The crude hospital mortality was significantly higher for patients with AKI than those without (42.7% versus 13.4%; odds ratio, 4.8; 95% confidence interval, 4.5 to 5.1; P < 0.0001). There was also a decrease in AKI crude mortality (annual percentage change, -3.4%; 95% confidence interval, -4.7 to -2.12; P < 0.001), however, which was not seen in patients without AKI. After covariate adjustment, AKI remained associated with a higher mortality (odds ratio, 1.23; 95% confidence interval, 1.14 to 1.32; P < 0.001) and there was a declining trend in the odds ratio for hospital mortality.

CONCLUSION

Over the past decade, in a large cohort of critically ill patients admitted to 20 Australian ICUs, there has been a significant rise in the incidence of early AKI while the mortality associated with AKI has declined.

Analysis of oral cancer epidemiology in the US reveals state-specific trends: implications for oral cancer prevention

Background

Downward trends have been observed in oral cancer incidence and mortality in the US over the past 30 years; however, these declines are not uniform within this population. Several studies have now demonstrated an increase in the incidence and mortality from oral cancers among certain demographic groups, which may have resulted from increased risks or risk behaviors. This study examines the underlying data that comprise these trends, to identify specific populations that may be at greater risk for morbidity and mortality from oral cancers.

Methods

Oral cancer incidence and mortality data analyzed for this study were generated using the National Cancer Institute's Surveillance, Epidemiology and End Results (SEER) program.

Results

While oral cancer incidence and mortality rates have been declining over the past thirty years, these declines have reversed in the past five years among some demographic groups, including black females and white males. Sorting of these data by state revealed that eight states exhibited increasing rates of oral cancer deaths, Nevada, North Carolina, Iowa, Ohio, Maine, Idaho, North Dakota, and Wyoming, in stark contrast to the national downward trend. Furthermore, a detailed analysis of data from these states revealed increasing rates of oral cancer among older white males, also contrary to the overall trends observed at the national level.

Conclusion

These results signify that, despite the declining long-term trends in oral cancer incidence and mortality nationally, localized geographic areas exist where the incidence and mortality from oral cancers have been increasing. These areas represent sites where public health education and prevention efforts may be focused to target these specific populations in an effort to improve health outcomes and reduce disparities within these populations.

In vivo confocal laser scanning chromo-endomicroscopy of colorectal neoplasia: changing the technological paradigm

Recently, miniaturization of a novel confocal laser endomicroscope (Optiscan Pty, Notting Hill, Victoria, Australia) has permitted functional integration into the distal tip of a conventional video colonoscope (Pentax EC3870K; Pentax, Tokyo, Japan) enabling imaging of the surface epithelium and the underlying lamina propria during ongoing video endoscopy. Using endomicroscopy and intravenous sodium fluorescein as a contrast agent, 'virtual histology' can be created, which allows visualization of both the surface epithelium, and some of the lamina propria (down to a quarter of a millimetre), including the microvasculature. Confocal endomicroscopy may have major implications in the future of colonoscopy as uniquely it allows in vivo diagnosis of colonic intraepithelial neoplasia and carcinoma enabling 'smart' biopsy targeting and hence potentially influencing 'on table' management decisions. Initial pilot data have now shown that confocal imaging in vivo using the newly developed EC3870K has high overall accuracy for the immediate diagnosis of intraepithelial neoplasia and carcinoma in sporadic screened cohorts, but also has a role in the detection of intraepithelial neoplasia detection in chronic ulcerative colitis cancer screening when used in conjunction with methylene blue chromoscopy. We discuss the current evidence in support of confocal endomicroscopy in the colorectum and explore the new diagnostic possibilities for this technology.

Hazard regression model and cure rate model in colon cancer relative survival trends: are they telling the same story?

Hazard regression models and cure rate models can be advantageously used in cancer relative survival analysis. We explored the advantages and limits of these two models in colon cancer and focused on the prognostic impact of the year of diagnosis on survival according to the TNM stage at diagnosis. The analysis concerned 9,998 patients from three French registries. In the hazard regression model, the baseline excess death hazard and the time-dependent effects of covariates were modelled using regression splines. The cure rate model estimated the proportion of 'cured' patients and the excess death hazard in 'non-cured' patients. The effects of year of diagnosis on these parameters were estimated for each TNM cancer stage. With the hazard regression model, the excess death hazard decreased significantly with more recent years of diagnoses (hazard ratio, HR 0.97 in stage III and 0.98 in stage IV, P < 0.001). In these advanced stages, this favourable effect was limited to the first years of follow-up. With the cure rate model, recent years of diagnoses were significantly associated with longer survivals in 'non-cured' patients with advanced stages (HR 0.95 in stage III and 0.97 in stage IV, P < 0.001) but had no significant effect on cure (odds ratio, OR 0.99 in stages III and IV, P > 0.5). The two models were complementary and concordant in estimating colon cancer survival and the effects of covariates. They provided two different points of view of the same phenomenon: recent years of diagnosis had a favourable effect on survival, but not on cure.

Thyroid cancer incidence and socioeconomic indicators of health care access

OBJECTIVE

It has been hypothesized that changes in diagnostic practices have driven the dramatic rise in thyroid cancer incidence over the past two decades. This study investigated the relation between the incidence of thyroid cancer and socioeconomic indicators of health care access.

METHODS

We examined thyroid cancer incidence trends in Wisconsin, USA, between 1980 and 2004, according to patient and tumor characteristics. Ecologic analyses were conducted by county to examine the relation between thyroid cancer incidence and education, income, and health insurance coverage.

RESULTS

The incidence of thyroid cancer nearly doubled in Wisconsin between 1980 and 2004, with almost all of the increase occurring between 1990 and 2004, during which an annual change of 4.0% (95% CI: 3.3-4.6) was observed. The bulk of the increase consisted of small, localized cancers of papillary histology. Ecologic analyses indicated moderate correlations by county between thyroid cancer incidence and median household income (r = 0.25), percent of residents with a college degree (r = 0.24), and percent of residents with health insurance (r = 0.41).

CONCLUSIONS

The association between thyroid cancer incidence and socioeconomic indicators of health care access is consistent with the hypothesis that the rising incidence trend is attributable to utilization of new diagnostic practices.

Modification by N-acetyltransferase 1 genotype on the association between dietary heterocyclic amines and colon cancer in a multiethnic study

OBJECTIVE

Colorectal cancer incidence is greater among African Americans, compared to whites in the U.S., and may be due in part to differences in diet, genetic variation at metabolic loci, and/or the joint effect of diet and genetic susceptibility. We examined whether our previously reported associations between meat-derived heterocyclic amine (HCA) intake and colon cancer were modified by N-acetyltransferase 1 (NAT1) or 2 (NAT2) genotypes and whether there were differences by race.

METHODS

In a population-based, case-control study of colon cancer, exposure to HCAs was assessed using a food-frequency questionnaire with a meat-cooking and doneness module, among African Americans (217 cases and 315 controls) and whites (290 cases and 534 controls).

RESULTS

There was no association with NAT1*10 versus NAT1-non*10 genotypes for colon cancer. Among whites, there was a positive association for NAT2-"rapid/intermediate" genotype [odds ratio (OR)=1.4; 95% confidence interval (CI)=1.0, 1.8], compared to the NAT2-"slow" that was not observed among African Americans. Colon cancer associations with HCA intake were modified by NAT1, but not NAT2, regardless of race. However, the "at-risk" NAT1 genotype differed by race. For example, among African Americans, the positive association with 2-amino-1-methyl-6-phenyl-imidazo[4,5-b]pyridine (PhIP) was confined to those with NAT1*10 genotype (OR=1.8; 95% CI=1.0, 3.3; P for interaction=0.02, comparing highest to lowest intake), but among whites, an association with 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) was confined to those with NAT1-non*10 genotype (OR=1.9; 95% CI=1.1, 3.1; P for interaction=0.03).

CONCLUSIONS

Our data indicate modification by NAT1 for HCA and colon cancer associations, regardless of race. Although the at-risk NAT1 genotype differs by race, the magnitude of the individual HCA-related associations in both race groups are similar. Therefore, our data do not support the hypothesis that NAT1 by HCA interactions contribute to differences in colorectal cancer incidence between African Americans and whites.

Q&A on diagnosis, screening and follow-up of colorectal neoplasia

The impressive and brisk evolution of medical science prevents many physicians from a thorough update on all the research fields. Colorectal cancer diagnosis, screening and follow-up is well known to require a multi-disciplinary approach, as it is faced by several specialties such as primary care physicians, gastroenterologists, non-gastroenterologist internists, radiologists and surgeons. To address this issue in a mutual perspective, we focused on the main points of the epidemiology, diagnosis, screening and follow-up of colorectal neoplasia by using a simple "Question & Answers" structure.

Serum markers for prostate cancer: a rational approach to the literature

INTRODUCTION

Due to its universal applicability for early detection and prediction of cancer stage and disease recurrence, widespread implementation of serum-based prostate-specific antigen (PSA) measurements has a significant influence on current treatment strategies for men with prostate cancer (PCa). However, over-detection and the resultant over-treatment of indolent cancers have been strongly implicated to occur. Using current recommended guidelines, the PSA test suffers from both limited sensitivity and specificity to enable efficacious population-based cancer detection. Therefore, novel biomarkers are much needed to complement PSA by enhancing its diagnostic and prognostic performance.

METHODS

The present literature on serum markers for PCa was reviewed. PSA derivatives, molecular PSA isoforms, and novel molecular targets in blood were summarized and weighted against their potential to improve decision-making of men with PCa.

RESULTS

Current evidence suggests that no single analyte is likely to achieve the desired level of diagnostic and prognostic accuracy for PCa. However, the combination of biomarkers with clinical and demographic data, for example, using established standard nomograms, has produced progress toward the goal of both optimal screening and risk assessment. Furthermore, potential candidate molecular markers for PCa can be derived from high-throughput technologies. Current studies demonstrate that understanding dynamic PSA changes over time may offer diagnostic and prognostic information.

CONCLUSIONS

Bridging the gap between basic science and clinical practice represents the main goal in the near future to enable physicians to tailor risk-adjusted screening and treatment strategies for current patients with PCa.

Small and diminutive polyps detected at screening CT colonography: a decision analysis for referral to colonoscopy

OBJECTIVE

The objective of this study was to assess the clinical and economic impact of colonoscopic referral for small and diminutive polyps detected at CT colonography (CTC) screening.

MATERIALS AND METHODS

A decision analysis model was constructed incorporating the expected polyp distribution, advanced adenoma prevalence, colorectal cancer (CRC) risk, CTC performance, and costs related to CRC screening and treatment. The model conservatively assumed that CRC risk was independent of advanced adenoma size. The number of diminutive (< or = 5 mm), small (6-9 mm), and large (> or = 10 mm) CTC-detected polyps needed to be removed to detect one advanced adenoma or prevent one CRC over a 10-year time horizon was calculated. The cost-effectiveness of polypectomy was also assessed.

RESULTS

The estimated 10-year CRC risk for unresected diminutive, small, and large polyps was 0.08%, 0.7%, and 15.7%, respectively. The number of diminutive, small, and large polyps needed to be removed to avoid leaving behind one advanced adenoma was 562, 71, and 2.5, respectively; similarly, 2,352, 297, and 10.7 polypectomies would be needed, respectively, to prevent one CRC over 10 years. The incremental cost-effectiveness ratio of removing all diminutive and small CTC-detected polyps was $464,407 and $59,015 per life-year gained, respectively. Polypectomy for large CTC-detected polyps yielded a cost-saving of $151 per person screened.

CONCLUSION

For diminutive polyps detected at CTC screening, the very low likelihood of advanced neoplasia and the high costs associated with polypectomy argue against colonoscopic referral, whereas removal of large CTC-detected polyps is highly effective. The yield of colonoscopic referral for small polyps is relatively low, suggesting that CTC surveillance may be a reasonable management option.