Abstract S5-6: Activating HER2 mutations in HER2 gene amplification negative breast cancers

Background: Breast cancer genome sequencing projects, performed by the genome sequencing centers in the U.S., Canada, and the U.K., are elucidating the somatic mutations and other genomic alterations that occur in human breast cancer. These studies recently identified somatic HER2 mutations in breast cancers lacking HER2 gene amplification.

Results: Compilation of data from seven sequencing studies documented 22 patients with somatic HER2 mutations. These mutations clustered in three regions. The first cluster was at amino acid (aa) 309–310 (exon 8), located in the extracellular domain. These aa residues form part of the HER2 dimerization interface. The second cluster was at aa 755–781, located in the kinase domain (exons 19–20). This was the most common location for HER2 mutations, with 17 out of 22 patients having somatic mutations here. The third region was at aa 835–896, also in the kinase domain (exons 21–22). Using multiple experimental approaches (cell line experiments, in vitro kinase assays, protein structure modeling, and xenograft experiments), we tested seven of these HER2 mutations and showed that 4 of them are activating mutations that are sensitive to lapatinib and trastuzumab. Another 2 mutations were found to be lapatinib resistant and we determined their sensitivity to neratinib, canertinib, and gefitinib.

Conclusions: These findings biologically validate somatic HER2 mutations as good targets for breast cancer treatment, but the appropriate choice of targeted drug is dependent on the precise mutation present. This study is among the first to functionally characterize mutations identified by breast cancer genome sequencing. A prospective, multi-institutional clinical trial has been launched to screen for HER2 mutation positive patients and determine the clinical outcome of treatment with HER2 targeted drugs.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr S5-6.

Lateral preference patterns as possible correlates of successfully switched left hand writing: Data and a theory

Left-handers often have had to contend with pressure to switch their preferred writing hand and shift attempt reports are common, especially among older adult left-handers. Three groups of left-handers can be defined by combining two variables, writing hand side and the report of a rightward hand preference shift attempt. The three groups are, first, right hand writers who report a rightward shift (successfully shifted left-handers); second, left hand writers who report a rightward shift attempt (unsuccessfully shifted left-handers); and, finally, left hand writers who do not report a rightward shift attempt. The underlying mechanisms that determine the success or failure of a handwriting shift attempt remain unclear. The present study examined the history of attempts to switch the preferred writing hand in a sample of 1277 adults aged 65 to 100 years of age. Older adults are well suited to participate in such a study because pressure to switch hand preference was especially severe for those who grew up in the early part of the 20th century; reports of rightward shift attempts are more common in this age group than among younger adults. Our results suggest that the three groups of left-handers, distinguished by the presence or absence of a shift history report and writing hand side, can also be distinguished from each other on the basis of their overall lateral preference profiles (the sides of hand, foot, eye, and ear preferences). Left hand writers, with and without reports of a rightward shift history, showed stronger left side lateralisation patterns when compared to right hand writers who reported a rightward switch (the successfully shifted left-handers).

Forgotten variables in memory theory and research

Memory research, like other scientific research, disregards many variables in order to bring the full force of the scientific method to bear on clearly important variables. The reasons why memory research attends to certain variables and disregards others emanate largely from theoretical assumptions that distinguish memory systems from other psychological systems, and that distinguish variables intrinsic to memory from those extrinsic to memory. Nevertheless, a number of these 'forgotten' variables affect memory performance. Regardless of past practice, it is a mistake for memory research to continue to ignore relevant variables. Doing so introduces measurement error that contaminates memory performance measures, and classification error that precludes the discovery of legitimate memory variables. It is proposed here that if forgotten memory variables are controlled, manipulated, and measured more extensively, then future memory research will have greater power and memory theories will have greater validity.

Relationship between birth order, birth stress, and lateral preferences: a critical review

Reviews the literature examining the relationship between birth order, birth stress, and lateral preferences in nonclinical samples, with special emphasis on reports since 1971. The review found no evidence to relate birth order position to deviations from right-sidedness for either sex. More direct measures of birth stress indicated that deviations from right-handedness (particularly for male subjects), and also right-eyedness, were statistically related to specific birth stressors. It should be stressed, however, that all the relationships, including the significant ones, were very weak, accounting for less than 1% of the variance. When statistical significance was achieved, it was largely due to the huge sample sizes used in the meta-analyses. Methological and theoretical problems exist in the current literature, and we offer some suggestions to resolve them.

Association between familial sinistrality and pathological left-handedness: a comparison of mentally retarded and nonretarded subjects

The hypothesis that familial sinistrality (FS) might be a useful variable for differentiating between pathological and natural left-handers was explored. A comparison of the incidence of FS in mentally retarded and nonretarded samples indicated that a positive history of familial sinistrality (FS+) was significantly more likely to occur in mildly retarded individuals. In addition, left-handed retarded people, in general, were significantly more likely to be FS+ than were right-handed retarded people.

Left sidedness and sleep difficulty: the alinormal syndrome

Four indexes of laterality: handedness, footedness, eyedness, and earedness, were assessed in a sample of 1274 subjects. Left- and right-sided groups were compared on two aspects of self-reported sleep difficulty: trouble falling asleep and frequent night wakenings. The incidence of sleep difficulty was found to be elevated in the left-sided groups. The results are discussed in terms of a possible complex of behavioral deviations from the statistical norm, called the alinormal syndrome.

Suspected autoimmune disorders and left-handedness: evidence from individuals with diabetes. Crohn's disease and ulcerative colitis

This study tested the theory that left-handedness is associated with certain disorders that may have an autoimmune aetiology. To accomplish this, we compared the handedness patterns of people with either Type I or Type II diabetes, Crohn's disease, or ulcerative colitis with a normal control group. Consistent with earlier findings, a significantly higher incidence of left-handedness was observed in people with either Crohn's disease or ulcerative colitis. In addition, there was evidence that males with Type I diabetes were more likely to be left-handed than males with Type II diabetes.

Birth stress and self-reported sleep difficulty

Difficulty in falling asleep and frequency of night wakenings were assessed in 1,272 college-aged individuals for whom birth histories (based on retrospective maternal reports) were available. A history of birth complications was associated with reports of sleep difficulties as an infant. Birth stressors, such as breech birth, prolonged labor, low birth weight, and multiple births, were predictive of disrupted sleep patterns in the young adult.

Writing hand posture and four indexes of lateral preference

The relationship between writing hand posture and lateral preference for hand, foot, eye, and ear was examined in a sample of 3709 college undergraduates. A markedly different pattern of lateral preferences was observed in left-handed males and females as a function of hand posture. Left-handed male inverters displayed a tendency toward more leftward lateral preferences in all four indexes; while it was found that hand inversion during writing in left-handed females reflected, if anything, a tendency toward more rightward lateral preferences.

The relationship between birth stress and writing hand posture

Variations in handwriting posture (inverted versus noninverted) were measured in 1203 individuals for whom birth histories, based upon retrospective maternal reports, were available. A history of birth complications was associated with an increased incidence of inverted handwriting posture. Effects interacted with sex and hand preference; the largest difference in handwriting posture between the birth-stressed and non-birth-stressed groups occurred in left-handers and in males.

Subject variables and cerebral organization for language

The present study investigated the usefulness of a variety of subject variables that have been proposed as having predictive value for determining cerebral organization for language. To accomplish this, a total of 373 subjects (117 left-handers and 256 right-handers) were given 240 trials of a consonant-vowel dichotic listening task to assess direction and degree of language lateralization. Each subject was also classified on the basis of eight subject variables (handedness, strength of handedness, familial sinistrality, writing hand posture, sex, sighting dominance, preferred footedness, and overall laterality). The results of the study indicated that left hemisphere language processing is very pervasive and that most of the subject variables examined were not very useful predictors of language lateralization. In addition, surprisingly, footedness and not handedness was the single best predictor of cerebral organization for language.