Uncontrolled cell proliferation is the hallmark of cancer, and tumor cells have typically acquired damage to genes that directly regulate their cell cycles. Genetic alterations affecting p16(INK4a) and cyclin D1, proteins that govern phosphorylation of the retinoblastoma protein (RB) and control exit from the G1 phase of the cell cycle, are so frequent in human cancers that inactivation of this pathway may well be necessary for tumor development. Like the tumor suppressor protein p53, components of this "RB pathway," although not essential for the cell cycle per se, may participate in checkpoint functions that regulate homeostatic tissue renewal throughout life.

http://science.sciencemag.org/content/sci/274/5293/1672.full.pdf

Cancer Cell Cycles

Objective. —To identify and quantify the major external (nongenetic) factors that contribute to death in the United States. Data Sources. —Articles published between 1977 and 1993 were identified through MEDLINE searches, reference citations, and expert consultation. Government reports and compilations of vital statistics and surveillance data were also obtained. Study Selection. —Sources selected were those that were often cited and those that indicated a quantitative assessment of the relative contributions of various factors to mortality and morbidity. Data Extraction. —Data used were those for which specific methodological assumptions were stated. A table quantifying the contributions of leading factors was constructed using actual counts, generally accepted estimates, and calculated estimates that were developed by summing various individual estimates and correcting to avoid double counting. For the factors of greatest complexity and uncertainty (diet and activity patterns and toxic agents), a conservative approach was taken by choosing the lower boundaries of the various estimates. Data Synthesis. —The most prominent contributors to mortality in the United States in 1990 were tobacco (an estimated 400000 deaths), diet and activity patterns (300 000), alcohol (100 000), microbial agents (90 000), toxic agents (60 000), firearms (35 000), sexual behavior (30 000), motor vehicles (25 000), and illicit use of drugs (20 000). Socioeconomic status and access to medical care are also important contributors, but difficult to quantify independent of the other factors cited. Because the studies reviewed used different approaches to derive estimates, the stated numbers should be viewed as first approximations. Conclusions. —Approximately half of all deaths that occurred in 1990 could be attributed to the factors identified. Although no attempt was made to further quantify the impact of these factors on morbidity and quality of life, the public health burden they impose is considerable and offers guidance for shaping health policy priorities. (JAMA. 1993;270:2207-2212)

https://jamanetwork.com/journals/JAMA/articlepdf/409171/jama_270_18_038.pdf

Actual causes of death in the United States.

Endostatin: an endogenous inhibitor of angiogenesis and tumor growth.

NOTE The report of the Committee without its annexes appears as Official Records of the General Assembly, Sixty-third Session, Supplement No. 46. The designations employed and the presentation of material in this publication do not imply the expression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning the legal status of any country, territory, city or area, or of its authorities, or concerning the delimitation of its frontiers or boundaries. The country names used in this document are, in most cases, those that were in use at the time the data were collected or the text prepared. In other cases, however, the names have been updated, where this was possible and appropriate, to reflect political changes. Scientific Annexes Annex A. Medical radiation exposures Annex B. Exposures of the public and workers from various sources of radiation INTROdUCTION 1. In the course of the research and development for and the application of atomic energy and nuclear technologies, a number of radiation accidents have occurred. Some of these accidents have resulted in significant health effects and occasionally in fatal outcomes. The application of technologies that make use of radiation is increasingly widespread around the world. Millions of people have occupations related to the use of radiation, and hundreds of millions of individuals benefit from these uses. Facilities using intense radiation sources for energy production and for purposes such as radiotherapy, sterilization of products, preservation of foodstuffs and gamma radiography require special care in the design and operation of equipment to avoid radiation injury to workers or to the public. Experience has shown that such technology is generally used safely, but on occasion controls have been circumvented and serious radiation accidents have ensued. 2. Reviews of radiation exposures from accidents have been presented in previous UNSCEAR reports. The last report containing an exclusive chapter on exposures from accidents was the UNSCEAR 1993 Report [U6]. 3. This annex is aimed at providing a sound basis for conclusions regarding the number of significant radiation accidents that have occurred, the corresponding levels of radiation exposures and numbers of deaths and injuries, and the general trends for various practices. Its conclusions are to be seen in the context of the Committee's overall evaluations of the levels and effects of exposure to ionizing radiation. 4. The Committee's evaluations of public, occupational and medical diagnostic exposures are mostly concerned with chronic exposures of …

sources and effects of ionizing radiation

Background Cetuximab is effective in platinum-resistant recurrent or metastatic squamous-cell carcinoma of the head and neck. We investigated the efficacy of cetuximab plus platinum-based chemotherapy as first-line treatment in patients with recurrent or metastatic squamous-cell carcinoma of the head and neck. Methods We randomly assigned 220 of 442 eligible patients with untreated recurrent or metastatic squamous-cell carcinoma of the head and neck to receive cisplatin (at a dose of 100 mg per square meter of body-surface area on day 1) or carboplatin (at an area under the curve of 5 mg per milliliter per minute, as a 1-hour intravenous infusion on day 1) plus fluorouracil (at a dose of 1000 mg per square meter per day for 4 days) every 3 weeks for a maximum of 6 cycles and 222 patients to receive the same chemotherapy plus cetuximab (at a dose of 400 mg per square meter initially, as a 2-hour intravenous infusion, then 250 mg per square meter, as a 1-hour intravenous infusion per week) for a maximum of 6 cycles. Patients with stable disease who received chemotherapy plus cetuximab continued to receive cetuximab until disease progression or unacceptable toxic effects, whichever occurred first. Results

/pdf/platinum-based-chemotherapy-plus-cetuximab-in-head-and-neck-2c129qnqh9.pdf

Platinum-Based Chemotherapy plus Cetuximab in Head and Neck Cancer

In this issue of the Journal, two papers address the role of radiation therapy in patients with breast cancer treated with adjuvant chemotherapy. These prospective, randomized trials from Denmark1 ...

Stopping metastases at their source.

Contralateral breast carcinoma: an assessment of risk and prognosis in stage I (T1N0M0) and stage II (T1N1M0) patients with 20-year follow-up.

Intratumoral injection of an adenoviral vector containing radiation-inducible DNA sequences of the Egr-1 promoter linked to a cDNA encoding tumor necrosis factor (TNF) alpha (Ad.Egr-TNF) enhances the tumoricidal action of ionizing radiation in a human epidermoid carcinoma xenograft (SQ-20B). The dominant histopathological feature in tumor-bearing animals treated with Ad.Egr-TNF and irradiation is extensive intratumoral vascular thrombosis and tumor necrosis. Thrombosis and necrosis are not observed in animals treated with either the viral construct encoding TNF-alpha or radiation and did not occur in irradiated normal tissues adjacent to tumor in animals injected with Ad.Egr-TNF. To determine if the occlusive effects of Ad.Egr-TNF and X-irradiation were specific for tumor vessels, non-tumor-bearing mice were irradiated after receiving i.m. injection of Ad.Egr-TNF at viral titers 20-100 times greater than titers injected intratumorally. No vascular thrombosis was observed in the treated normal tissues. Combined Ad.Egr-TNF and radiation produced occlusion of tumor microvessels without significant normal tissue damage. Taken together, these data suggest that the interaction between radiation inducible TNF-alpha and X-irradiation occurs selectively within the tumor vessels.

https://cancerres.aacrjournals.org/content/canres/56/19/4311.full.pdf

Tumor necrosis factor α (TNF-α) gene therapy targeted by ionizing radiation selectively damages tumor vasculature

The effect of 17β-estradiol on an estrogen receptor-positive human breast cancer cell line (MCF-7) was studied. Low concentrations (10 -9 m) of 17β-estradiol enhanced the rate of cell proliferation; the overall cell cycle time was shortened; and the proportion of cells in the S phase increased. Higher concentrations (10 -7 m) suppressed proliferation and slightly decreased the proportion of cells in DNA synthesis. When combined with 1-β-d-arabinofuranosylcytosine, an S-phase-specific chemotherapeutic agent, 10 -9 m 17β-estradiol enhanced cell killing. This enhancement was not observed with 10 -7 m 17β-estradiol. Kinetic changes caused by hormones have profound implications in clinical therapy, since the efficacy of cycle active agents may be altered.

Proliferation Kinetics of a Human Breast Cancer Line in Vitro following Treatment with 17β-Estradiol and 1-β-d-Arabinofuranosylcytosine

AFTER the introduction of supervoltage equipment into clinical practice some 25 years ago, radiation therapy assumed an increasingly prominent role in the management of patients with cancer. Current estimates are that 50 per cent of patients with cancer will receive radiation therapy at some time during the course of their disease, and a large percentage of these patients will be treated with curative intent. Survival rates approximating 90 per cent are reported by many centers treating early seminoma of the testis, Hodgkin's disease, and cancers of the larynx and cervix. Impressive results have recently been reported in prostatic cancer1 and . . .

Samuel Hellman

Papers

Stopping metastases at their source.

Contralateral breast carcinoma: an assessment of risk and prognosis in stage I (T1N0M0) and stage II (T1N1M0) patients with 20-year follow-up.

Tumor necrosis factor α (TNF-α) gene therapy targeted by ionizing radiation selectively damages tumor vasculature

Proliferation Kinetics of a Human Breast Cancer Line in Vitro following Treatment with 17β-Estradiol and 1-β-d-Arabinofuranosylcytosine

Normal Tissue Responses to Radiation Therapy