Systematic review and meta-analysis

Breast cancer patients with the same stage of disease can have markedly different treatment responses and overall outcome. The strongest predictors for metastases (for example, lymph node status and histological grade) fail to classify accurately breast tumours according to their clinical behaviour. Chemotherapy or hormonal therapy reduces the risk of distant metastases by approximately one-third; however, 70-80% of patients receiving this treatment would have survived without it. None of the signatures of breast cancer gene expression reported to date allow for patient-tailored therapy strategies. Here we used DNA microarray analysis on primary breast tumours of 117 young patients, and applied supervised classification to identify a gene expression signature strongly predictive of a short interval to distant metastases ('poor prognosis' signature) in patients without tumour cells in local lymph nodes at diagnosis (lymph node negative). In addition, we established a signature that identifies tumours of BRCA1 carriers. The poor prognosis signature consists of genes regulating cell cycle, invasion, metastasis and angiogenesis. This gene expression profile will outperform all currently used clinical parameters in predicting disease outcome. Our findings provide a strategy to select patients who would benefit from adjuvant therapy.

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Gene expression profiling predicts clinical outcome of breast cancer

Background A more accurate means of prognostication in breast cancer will improve the selection of patients for adjuvant systemic therapy. Methods Using microarray analysis to evaluate our previously established 70-gene prognosis profile, we classified a series of 295 consecutive patients with primary breast carcinomas as having a gene-expression signature associated with either a poor prognosis or a good prognosis. All patients had stage I or II breast cancer and were younger than 53 years old; 151 had lymph-node–negative disease, and 144 had lymph-node–positive disease. We evaluated the predictive power of the prognosis profile using univariable and multivariable statistical analyses. Results Among the 295 patients, 180 had a poor-prognosis signature and 115 had a good-prognosis signature, and the mean (±SE) overall 10-year survival rates were 54.6±4.4 percent and 94.5±2.6 percent, respectively. At 10 years, the probability of remaining free of distant metastases was 50.6±4.5 percent in the group with a...

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A Gene-Expression Signature as a Predictor of Survival in Breast Cancer

Background: The finding of a decrease in contralateral breast cancer incidence following tamoxifen administration for adjuvant therapy led to the concept that the drug might play a role in breast cancer prevention. To test this hypothesis, the National Surgical Adjuvant Breast and Bowel Project initiated the Breast Cancer Prevention Trial (P-1) in 1992. Methods: Women (N = 13 388) at increased risk for breast cancer because they 1) were 60 years of age or older, 2) were 35‐59 years of age with a 5-year predicted risk for breast cancer of at least 1.66%, or 3) had a history of lobular carcinoma in situ were randomly assigned to receive placebo (n = 6707) or 20 mg/day tamoxifen (n = 6681) for 5 years. Gail’s algorithm, based on a multivariate logistic regression model using combinations of risk factors, was used to estimate the probability (risk) of occurrence of breast cancer over time. Results: Tamoxifen reduced the risk of invasive breast cancer by 49% (two-sided P<.00001), with cumulative incidence through 69 months of follow-up of 43.4 versus 22.0 per 1000 women in the placebo and tamoxifen groups, respectively. The decreased risk occurred in women aged 49 years or younger (44%), 50‐59 years (51%), and 60 years or older (55%); risk was also reduced in women with a history of lobular carcinoma in situ (56%) or atypical hyperplasia (86%) and in those with any category of predicted 5-year risk. Tamoxifen reduced the risk of noninvasive breast cancer by 50% (two-sided P<.002). Tamoxifen reduced the occurrence of estrogen receptor-positive tumors by 69%, but no difference in the occurrence of estrogen receptor-negative tumors was seen. Tamoxifen administration did not alter the average annual rate of ischemic heart disease; however, a reduction in hip, radius (Colles’), and spine fractures was observed. The rate of endometrial cancer was increased in the tamoxifen group (risk ratio = 2.53; 95% confidence interval = 1.35‐4.97); this increased risk occurred predominantly in women aged 50 years or older. All endometrial cancers in the tamoxifen group were stage I (localized disease); no endometrial cancer deaths have occurred in this group. No liver cancers or increase in colon, rectal, ovarian, or other tumors was observed in the tamoxifen group. The rates of stroke, pulmonary embolism, and deep-vein thrombosis were elevated in the tamoxifen group; these events occurred more frequently in women aged 50 years or older. Conclusions: Tamoxifen decreases the incidence of invasive and noninvasive breast cancer. Despite side effects resulting from administration of tamoxifen, its use as a breast cancer preventive agent is appropriate in many women at increased risk for the disease. [J Natl Cancer Inst 1998;90:1371‐88]

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Tamoxifen for Prevention of Breast Cancer: Report of the National Surgical Adjuvant Breast and Bowel Project P-1 Study

Background We present the combined results of two trials that compared adjuvant chemotherapy with or without concurrent trastuzumab in women with surgically removed HER2-positive breast cancer. Methods The National Surgical Adjuvant Breast and Bowel Project trial B-31 compared doxorubicin and cyclophosphamide followed by paclitaxel every 3 weeks (group 1) with the same regimen plus 52 weeks of trastuzumab beginning with the first dose of paclitaxel (group 2). The North Central Cancer Treatment Group trial N9831 compared three regimens: doxorubicin and cyclophosphamide followed by weekly paclitaxel (group A), the same regimen followed by 52 weeks of trastuzumab after paclitaxel (group B), and the same regimen plus 52 weeks of trastuzumab initiated concomitantly with paclitaxel (group C). The studies were amended to include a joint analysis comparing groups 1 and A (the control group) with groups 2 and C (the trastuzumab group). Group B was excluded because trastuzumab was not given concurrently with paclit...

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Trastuzumab plus adjuvant chemotherapy for operable HER2-positive breast cancer

Scientists continue to argue about the benefits of breast screening, but ultimately decisions about screening should be made by women themselves. To make this decision, however, women need to fully understand both the benefits and the potential harms.

Women need better information about routine mammography

The role played by steroid hormones in regulating the sexual behavior of female primates is reviewed, with emphasis placed on experiments using nonhuman species. A distinction is made between the effects of hormones on female proceptivity (i.e., behaviors which incite mounting activity in the male) and receptivity (i.e., willingness to accept male mounting attempts). The rationale for distinguishing between proceptivity and receptivity is discussed, and the methods used for measuring each are described. Evidence shows that estrogen of ovarian origin facilitates sexual interaction primarily by stimulating the emission of nonbehavioral cues which increase the female's sexual attractivity (i.e., the value of a female as a sexual stimulant for a male). Evidence is presented suggesting that estrogen may enhance proceptivity by acting on the female's central nervous system; however, there is no clear demonstration that estrogen affects neural mechanisms controlling receptivity. Experiments show that proceptivity and to a lesser extent receptivity are modulated by adrenal androgens, and the possibility is raised that adrenal androgens may act synergistically with estrogen to facilitate sexual behavior. A disruptive effect of progesterone on sexual interaction is described, and evidence is presented suggesting that this effect of progesterone results primarily from a reduction in sexual attractivity caused by the action of the hormone in the female's vagina. Other literature indicates that proceptivity is often maximal at the periovulatory period of the female primate's menstrual cycle whereas cyclic variations in receptivity occur infrequently. Most hormone-dependent changes in sexual interaction associated with the menstrual cycle seem to result from fluctuations in nonbehavioral attributes of female sexual attractivity. The problem of distinguishing between the effects of steroid hormones on proceptivity and receptivity in human females is discussed.

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Hormonal basis of proceptivity and receptivity in female primates.

More than 30 years have passed since the publication ( I ) showing that transplacental administration of testosterone to female guinea-pigs caused permanent changes in their ability to exhibit reproductive behaviours in response to ovarian steroids in adulthood. Over the intervening years articles have appeared which have extended this type of observation to numerous other mammalian species, including rat, hamster, gerbil, mouse, dog, ferret, pig, sheep, rhesus monkey, and marmoset (2, 3). In many instances inferences have been made about the probable existence of steroid-induced changes in the structure and function of the nervous system which underlie these changes in behaviour. These so-called ‘organizational’ effects of perinatal steroid exposure on the developing nervous system are often distinguished from the later ‘activational’ effects of these same steroids on the expression of sociosexual behaviours in adulthood. The number of different mammalian species used for mechanistic studies on the organizational effects of steroids, such as determining the precise perinatal timing of hormone action, the identity of the steroid(s) responsible for behavioural sexual differentiation, and the neural sites of steroid action, has been relatively small, and generally restricted to rodents. In the late 1970’s sex steroids acting during development were first implicated in the differentiation of sexually dimorphic telencephalic structures in passerine song birds which control singing associated with courtship (4, 5) . Since this early work, numerous studies have exploited the canary and zebra finch to explore mechanisms of steroid action in controlling the ontogeny of song in the male and the underlying changes in the nervous system. Other studies using the rat have explored in detail the role of androgen and oestrogen in controlling the differentiation in males of patterns of reproductive behaviour (2) as well as aspects of neural sex dimorphisms in the preoptic area/anterior hypothalamus (POA/AH) (6) and in the lumbar spinal cord (7). The concentration of mechanistic (behavioural, biochemical, neuroanatomical) studies of steroidal effects on sexually dimorphic behavioural potential in a few avian and rodent species is understandable, in light of their relative availability, low expense, and rapid time-course of neural development. Despite the substantial progress already made using these lower vertebrate models in promoting our understanding of how sex steroids influence neural and behavioural development, extrapolation of the results obtained in these studies to higher mammals including man cannot occur in the absence of some degree of empirical verification. Obviously, experimental manipulations of steroidal exposure during the development of human subjects would be unethical, thus we are left with experiments of nature (e.g. congenital adreno-genital syndrome,androgen insensitivity syndrome, and Sa-reductase deficient pseudohermaphroditism; details in later sections) with which to ask questions about the role of sex steroids in controlling psychosexual development in man. This work using clinical populations has been complemented by studies (8, 9) on two populations of rhesus female pseudohermaphrodites, created by transplacental administration of either testosterone or dihydrotestosterone (DHT) and by a study of female pseudohermaphroditic marmosets created by neonatal treatment with testosterone (10). While highly informative as far as they go, this research has not led to mechanistic studies using non-human primates to explore such questions as the critical perinatal periods of steroid action, the relative role of oestrogens versus androgens in controlling behavioural sexual differentiation in the male, or the relationship between steroidal control of sex dimorphisms in brain structure and behaviour. We have used the European ferret (Mustelufuro) in a n effort to develop a model system in which such questions can be addressed in a higher mammal. This carnivore is ideally suited for such experiments in that it is commercially available at a reasonable cost, is easily kept and handled in the laboratory, and produces relatively large litters (6 to 12 kits) which are born in an altricial state after a relatively short gestation (41 days) and which reach adulthood within 5 months. Normally, ferrets breed seasonally in response to lengthening photoperiod. A commercial breeder (Marshall Farms, North Rose, NY, USA) provides pregnant ferrets for our experiments throughout the year by the judicious use of artificial photoperiods in their breeding facility. Upon arrival in the laboratory, all ferrets used in our research are continuously

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1365-2826.1990.tb00425.x

Steroidal control of behavioural, neuroendocrine and brain sexual differentiation: studies in a carnivore, the ferret.

Whole body content of androgen (testosterone + 5 alpha-dihydrotestosterone) was invariably higher in male than in female rat pups killed 1 or 3 h after natural delivery, whereas androgen content was equivalent in males and females killed immediately or 6, 12, and 24 h after birth. Testicular content of androgen was significantly elevated in males killed 1 and 24 h after birth, compared with levels in males killed immediately, or 3, 6, and 12 h after birth. Thus, heightened testicular androgen content was only initially associated with increased systemic levels of androgen in males during the immediate postpartum period. A second study assessed the possibility that the body's clearance (i.e., metabolism plus excretion) of testosterone is lower in newborn rats upon separation from the placental circulation than in slightly older pups. Rats of both sexes killed 1 and 3 h after s.c. injection of [3H] testosterone had significantly higher plasma concentrations of [3H] testosterone as well as several 5 alpha-reduced androgens (5 alpha-dihydrotestosterone, 3 alpha-androstanediol, and androsterone) when injections were given within minutes as opposed to 24 h after birth. This suggests that in both sexes the clearance of testosterone is slower immediately after birth than at later ages. This phenomenon together with a brief postnatal elevation in the testicular synthesis and secretion of testosterone may explain the temporary rise in circulating androgen concentrations that occurs in the newborn male rat.

Immediate postnatal rise in whole body androgen content in male rats: correlation with increased testicular content and reduced body clearance of testosterone.

Michael J. Baum

Papers

Women need better information about routine mammography

Hormonal basis of proceptivity and receptivity in female primates.

Steroidal control of behavioural, neuroendocrine and brain sexual differentiation: studies in a carnivore, the ferret.

Immediate postnatal rise in whole body androgen content in male rats: correlation with increased testicular content and reduced body clearance of testosterone.

Mounting and receptive behavior in the ovariectomized female rat: Influence of estradiol, dihydrotestosterone, and genital anesthetization