Neo-antigen specific T cell responses indicate the presence of metastases before imaging.

Non-small cell lung cancer (NSCLC) causes 19% of all Australian cancer deaths, with a 5-year survival post-resection of around 60%. Post-operative recurrence is due to metastases that were undetectable pre-operatively, or growth of microscopic locoregional residual disease. However, post-operative imaging modalities typically only detect more advanced tumours; where PET-CT has a detection limit of 6-7 mm. Detection of small deposits of lung metastatic disease is of importance in order to facilitate early and potentially more effective treatment. In this study, in a murine model of lung metastatic disease, we explore whether neo-antigen specific T cells are a sensitive marker for the detection of lung cancer after primary tumour resection. We determine lung metastatic disease by histology, and then compare detection by PET-CT and neo-antigen specific T cell frequency. Detection of lung metastatic disease within the histology positive group by PET-CT and neo-antigen specific T cell frequency were 22.9% and 92.2%, respectively. Notably, neo-antigen specific T cells in the lung draining lymph node were indicative of metastatic disease (82.8 ± 12.9 spots/105 cells; mean ± SE), compared to healthy lung control (28.5 ± 8.6 spots/105 cells; mean ± SE). Potentially, monitoring tumour neo-antigen specific T cell profiles is a highly sensitive method for determining disease recurrence.

How reassuring is a normal breast ultrasound in assessment of a screen-detected mammographic abnormality? A review of interval cancers after assessment that included ultrasound evaluation.

AIM: To review factors resulting in a false-negative outcome or delayed cancer diagnosis in women recalled for further evaluation, including ultrasound, after an abnormal screening mammogram. MATERIALS AND METHODS: Of 646,692 screening mammograms performed between 1 January 1995 and 31 December 2004, 34,533 women were recalled for further assessment. Nine hundred and sixty-four interval cancers were reported in this period. Forty-six of these women had been recalled for further assessment, which specifically included ultrasound evaluation in the preceding 24 months, and therefore, met the inclusion criteria for this study. Screening mammograms, further mammographic views, ultrasound scans, clinical findings, and histopathology results were retrospectively reviewed by two consultant breast radiologists. RESULTS: The interval cancer developed in the contralateral breast (n=9), ipsilateral breast, but different site (n=6), and ipsilateral breast at the same site (n=31) as the abnormality for which they had recently been recalled. In the latter group, 10 were retrospectively classified as a false-negative outcome, nine had a delay in obtaining a biopsy, and 12 had a delay due to a non-diagnostic initial biopsy. Various factors relating to these outcomes are discussed. CONCLUSION: Out of 34,533 women who attended for an assessment visit and the 46 women who subsequently developed an interval breast cancer, 15 were true interval cancers, 10 had a false-negative assessment outcome, and 21 had a delay to cancer diagnosis on the basis of a number of factors. When there is discrepancy between the imaging and histopathology results, a repeat biopsy rather than early follow-up would have avoided a delay in some cases. A normal ultrasound examination should not deter the radiologist from proceeding to stereotactic biopsy, if the index mammographic lesion is suspicious of malignancy.

Pseudoangiomatous stromal hyperplasia: a study of the mammographic and sonographic features.

AIM: To review the imaging features on mammogram and ultrasound of pseudoangiomatous stromal hyperplasia (PASH) of the breast. MATERIALS AND METHODS: A systematic search of the breast cancer screening centre and pathology department database at a teaching hospital was performed to identify cases reported as PASH between 2000 and 2007. The findings on mammogram and ultrasound were reviewed. Information on demographics and clinical outcome were obtained from the patient's medical records. RESULTS: Seventy-three cases of PASH were identified, which occurred in women with a mean age of 51.1 +/- 10.5 years. The mean size of the lesion was 18 mm. Up to 70.8% of cases were radiologically detected and 29.2% presented as palpable masses. The most common appearance on mammography was of a solitary, non-calcified mass (30.4%) or localized increased stroma (30.4%). The distribution of mammographic findings differed in screen-detected patients compared with those presenting clinically (p = 0.015, Fisher's exact test). The most frequent sonographic appearance was of a well-defined hypoechoic mass (36.7%). CONCLUSION: Although there are emerging patterns associated with PASH on imaging, the features are not sufficiently specific to allow for a prospective diagnosis. Histological confirmation, preferably with core biopsy, should always be considered.