Dynamic Contrast-Enhanced MRI-Derived Intracellular Water Lifetime (τ i ): A Prognostic Marker for Patients with Head and Neck Squamous Cell Carcinomas

BACKGROUND AND PURPOSE

Shutter-speed model analysis of dynamic contrast-enhanced MR imaging allows estimation of mean intracellular water molecule lifetime (a measure of cellular energy metabolism) and volume transfer constant (a measure of hemodynamics). The purpose of this study was to investigate the prognostic utility of pretreatment mean intracellular water molecule lifetime and volume transfer constant in predicting overall survival in patients with squamous cell carcinomas of the head and neck and to stratify p16-positive patients based upon survival outcome.

MATERIALS AND METHODS

A cohort of 60 patients underwent dynamic contrast-enhanced MR imaging before treatment. Median, mean intracellular water molecule lifetime and volume transfer constant values from metastatic nodes were computed from each patient. Kaplan-Meier analyses were performed to associate mean intracellular water molecule lifetime and volume transfer constant and their combination with overall survival for the first 2 years, 5 years, and beyond (median duration, >7 years).

RESULTS

By the last date of observation, 18 patients had died, and median follow-up for surviving patients (n = 42) was 8.32 years. Patients with high mean intracellular water molecule lifetime (4 deaths) had significantly (P = .01) prolonged overall survival by 5 years compared with those with low mean intracellular water molecule lifetime (13 deaths). Similarly, patients with high mean intracellular water molecule lifetime (4 deaths) had significantly (P = .006) longer overall survival at long-term duration than those with low mean intracellular water molecule lifetime (14 deaths). However, volume transfer constant was a significant predictor for only the 5-year follow-up period. There was some evidence (P < .10) to suggest that mean intracellular water molecule lifetime and volume transfer constant were associated with overall survival for the first 2 years. Patients with high mean intracellular water molecule lifetime and high volume transfer constant were associated with significantly (P < .01) longer overall survival compared with other groups for all follow-up periods. In addition, p16-positive patients with high mean intracellular water molecule lifetime and high volume transfer constant demonstrated a trend toward the longest overall survival.

CONCLUSIONS

A combined analysis of mean intracellular water molecule lifetime and volume transfer constant provided the best model to predict overall survival in patients with squamous cell carcinomas of the head and neck.

Sorafenib targets BRAF and VEGFR in metastatic thyroid carcinoma

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Background. There is no effective therapy for patients with metastatic thyroid cancer not cured by surgery or treatment with I131. Sorafenib is a promising multi-tyrosine kinase inhibitor for patients with metastatic PTC (mPTC). Although the primary targets of sorafenib are thought to include BRAF and VEGFR, this has been the subject of debate. Whether sorafenib primarily acts on the tumor cells (TC) or endothelial cells (EC) and how BRAF mutation status (45% of PTC harbor V600E) relates to response is also unknown. Methods. Responses of patients with metastatic, iodine-refractory PTC, enrolled into our phase II study of sorafenib were monitored by PET at 4 wks and CTs every 2 mos. Sorafenib activity was studied using immunohistochemistry (IHC) for pERK, pAKT, and pVEGFR-2, while Ki-67 showed proliferating cells in tumor tissue pre- and on treatment. BRAF mutation status was determined by DNA sequencing. Results. Of 15 patients, five patients achieved a PR, three are stable (SD), two progressed, and three patients with SD withdrew due to toxicity. Target lesions decreased on average 31%. Eight of 10 PET scans showed decreased activity at 4 weeks. IHC on tissue from 2 patients (at 1 and 2 wks, both BRAFwt) showed 50% decrease in pERK (downstream of VEGFR2 and BRAF) and 30% decrease in pAKT (downstream of VEGFR2). p-ERK and p-AKT were altered in both the TC and EC. Ki-67 decreased from 10% to <1%. No change in VEGFR-2 was seen; but, pVEGFR-2 completely disappeared in one sample while the other showed a small decrease. Quantitative analysis using a multispectral imaging system confirmed the changes observed by IHC. In tissue from a patient at 17 months on sorafenib, the decrease in pERK and pAKT appeared to be the same or reversed, suggesting compensatory changes in these pathways in resistant but stable disease. Conclusions. Our study shows the early clinical and biologic activity of sorafenib in patients with mPTC and the targets of early suppression. Importantly, it also reveals compensatory changes in target molecules in cells resistant to therapy. These cells are the likely source of tumor resistance that has been seen to develop to other similar targeted agents. Sorafenib is the first viable treatment option for patients with mPTC, and these results provide key insights into the mechanisms of action and resistance of this drug.

No significant financial relationships to disclose.

Thyroid carcinoma after Chernobyl latent period, morphology and aggressiveness

The large numbers of papillary thyroid carcinomas that have occurred in those exposed to high levels of short-lived isotopes in fallout after Chernobyl provide a unique opportunity to correlate latency and tumour biology. We show that short latency is associated with tumours with a phenotype that is significantly less structurally differentiated, shows significantly less peritumour fibrosis, and significantly more invasive spread when compared to tumours with a longer latent period. In contrast, the type of differentiation (papillary or follicular architecture) is associated with age at exposure. These findings suggest that the initial mutation at the time of exposure played a major role in tumour latency and aggressiveness. We and others have shown that RET-PTC3 rearrangements are associated with the solid morphology seen in these short latency tumours, while classical papillary carcinomas more often show RET-PTC1 rearrangements. Studies in transgenic mice show similar findings, and in vitro studies show that RET-PTC3 induces more rapid growth than RET-PTC1. We therefore suggest that the solid morphology, high frequency of RET-PTC3 rearrangements and aggressive behaviour noted in early investigations of post-Chernobyl tumours were characteristic of short latency rather than the nature of the mutagen, and that successive overlapping waves of papillary carcinoma with differing latency, differing patterns of mutations and differing clinical behaviour are occurring in those exposed to Chernobyl fallout.

Gene expression in papillary thyroid carcinoma reveals highly consistent profiles

Papillary thyroid carcinoma (PTC) is clinically heterogeneous. Apart from an association with ionizing radiation, the etiology and molecular biology of PTC is poorly understood. We used oligo-based DNA arrays to study the expression profiles of eight matched pairs of normal thyroid and PTC tissues. Additional PTC tumors and other tissues were studied by reverse transcriptase-PCR and immunohistochemistry. The PTCs showed concordant expression of many genes and distinct clustered profiles. Genes with increased expression in PTC included many encoding adhesion and extracellular matrix proteins. Expression was increased in 8/8 tumors for 24 genes and in 7/8 tumors for 22 genes. Among these genes were several previously known to be overexpressed in PTC, such as MET, LGALS3, KRT19, DPP4, MDK, TIMP1, and FN1. The numerous additional genes include CITED1, CHI3L1, ODZ1, N33, SFTPB, and SCEL. Reverse transcriptase-PCR showed high expression of CITED1, CHI3L1, ODZ1, and SCEL in 6/6 additional PTCs. Immunohistochemical analysis detected CITED1 and SFTPB in 49/52 and 39/52 PTCs, respectively, but not in follicular thyroid carcinoma and normal thyroid tissue. Genes underexpressed in PTC included tumor suppressors, thyroid function-related proteins, and fatty acid binding proteins. Expression was decreased in 7/8 tumors for eight genes and decreased in 6/8 tumors for 19 genes. We conclude that, despite its clinical heterogeneity, PTC is characterized by consistent and specific molecular changes. These findings reveal clues to the molecular pathways involved in PTC and may provide biomarkers for clinical use.

Surgical and pathological changes after percutaneous ethanol injection therapy of thyroid nodules

Few data exist on the operative and pathological findings in patients having undergone previous percutaneous ethanol injection (PEI) therapy of thyroid nodules. We report here our experience with 13 patients operated on by the same surgical team. Two pathologists, both blinded to the previous PEI treatment, carried out histological evaluation. Reasons for surgery included PEI failure, suspicion of malignancy, and tracheal compression. The operations did not pose any special problem from the technical point of view, and the postoperative courses were uneventful. One patient who had a second operation developed hypoparathyroidism, and laryngeal nerve palsy was never observed. The histological diagnosis was hyperplastic or adenomatous nodule in 12 cases and papillary thyroid cancer in 1. No difficulty was found in evaluating the nodule capsule and surrounding vessels. In two lesions, nuclear enlargement and clearing were identified in thyroid follicles immediately adjacent to necrotic or scarred areas. These changes were considered reactive. In conclusion, patients previously treated by PEI were operated on without special technical problems. Histological diagnosis was not hindered, and there was no difficulty in ruling out malignant lesions. PEI, however, should be performed only by skilled operators, and incidental ethanol seepage throughout the nodule capsule must be carefully avoided.

Providing human tissues for research: how to establish a program

The Cooperative Human Tissue Network is a group composed of cooperating academic institutions that supply human tissues to researchers studying a wide range of neoplastic and other diseases. The experience of the Cooperative Human Tissue Network in establishing methods of prospective tissue collection and in developing tumor banks is discussed to aid institutions in establishing tissue resources for their local investigators, who may wish to use human tissues in current or future research projects. The advantages to pathology departments and to associated medical institutions of establishing an organized tissue resource include ensuring proper institutional review board approval of research projects using human tissues, protecting diagnostic specimens, creating new opportunities for extramural research, increasing the speed of diagnostic specimen transport to surgical pathology, and providing educational and research opportunities for pathologists and pathology residents. Methods of tissue collection, processing, storage, data collection, and supply are outlined. Also, resources necessary to begin organized tissue collection, including personnel, space, equipment, and supplies, are discussed.

Malignant granular cell tumors: report of a case and review of the literature

BACKGROUND

Granular cell tumors are uncommon soft tissue tumors and are more commonly benign. Malignant granular cell tumors are extremely rare, may be confused with other soft tissue sarcomas, and can be diagnosed only when metastatic disease that has the same histologic features as the primary tumor has been identified. Metastases are more commonly seen in lymph nodes and lungs; however, often the metastatic disease is not identified at the time of initial diagnosis and presents anywhere from 3 to 37 months after initial treatment. Certain findings, such as histologic appearance and size, may suggest that a granular cell tumor has uncertain malignant potential.

METHODS

We evaluated a patient with a granular cell tumor of uncertain malignant potential of the left chest wall and no evidence of metastatic disease on physical examination with a preoperative work-up to identify sites of occult disease.

RESULTS

The patient was found to have suspicious ipsilateral axillary adenopathy on magnetic resonance imaging and computed tomography scan. No other regional or distant disease was identified. The patient underwent an en bloc wide excision and axillary lymph node dissection. Metastatic disease was identified in nine of 23 lymph nodes.

CONCLUSIONS

Patients who are diagnosed with a granular cell tumor of uncertain malignant potential may benefit from preoperative radiologic evaluation because occult metastatic disease may be identified, alter the surgical approach, and possibly affect the long-term outcome.

Appendiceal carcinoma metastatic to the ovaries and mimicking primary ovarian tumors

Primary appendiceal carcinomas are a rare source of metastases to the ovaries. Three cases are reported here, and 25 others are reviewed from the English literature. The recognition of this entity is important, since the metastases may mimic an ovarian primary tumor clinically, and because of the propensity for a recognized appendiceal carcinoma to relapse in the ovaries. Therapeutic implications dictate that the appendix should always be carefully examined during exploration for ovarian masses, and prophylactic appendectomy should be considered, as part of the treatment of ovarian carcinomas.

Quantitative bone histomorphometry in humoral hypercalcemia of malignancy: uncoupling of bone cell activity

Humoral hypercalcemia of malignancy (HHM) results from elaboration by tumors of a circulating bone-resorbing factor(s). THe specific mechanism responsible for this bone resorption is poorly understood, and no comprehensive study employing quantitative histomorphometric analyses of bone biopsies obtained from living patients with HHM has been reported. We describe bone histology and quantitative bone histomorphometry in bone biopsies obtained from seven patients defined biochemically (elevated nephrogenous cAMP excretion) and histologically (no tumor in biopsy sample) as having HHM. These biopsies are compared to biopsies from nine patients with primary hyperparathyroidism (HPT). Compared to patients with HPT, those with HHM displayed (mean +/- SD) greater osteoclastic activity (osteoclast surface, 8.6 +/- 6.1% vs. 2.7 +/- 1.5%; P less than 0.001) and more frequent empty lacunae (9.2 +/- 4.0% vs. 5.8 +/- 3.0%; P less than 0.01), but markedly reduced osteoblastic surface (2.5 +/- 3.1% vs. 13.8 +/- 7.0%; P less than 0.001), osteoid surface (12.9 +/- 11.9% vs. 42.0 +/- 15.0%; P less than 0.001), and osteoid volume (0.3 +/- 0.3% vs. 1.3 +/- 1.0%; P less than 0.01). These findings directly confirm the presence of humorally mediated bone resorption and indicate a striking uncoupling of osteoclast and osteoblast activities in bone from patients with HHM. These findings are in sharp contrast to those in HPT patients, where osteoclast and osteoblast activities are tightly coupled, and net skeletal calcium loss is minimal. This uncoupling provides a mechanism for the marked skeletal calcium losses observed in patients with HHM.

Twenty-five year experience with primary hyperparathyroidism at Columbia Presbyterian Medical Center

A retrospective review of 500 patients with primary hyperparathyroidism seen from 1951 to 1975 was conducted; the effect of routine screening of calcium and phosphate levels (initiated in 1968) on the incidence and spectrum of the disease was analyzed. The majority of the patients (77%) were diagnosed in the eight-year period after routine biochemical screening was instituted. Comparing the group of patients diagnosed before the advent of biochemical screening and those diagnosed since screening was instituted, we found: (1) a small but significant increase in the number of asymptomatic patients diagnosed (from 2% to 12%); (2) no change in the incidence of related medical disorders, i.e., nephrocalcinosis and hypertension; (3) no change in the incidence of primary hyperplasia and adenoma; and (4) no change in the mean serum calcium level, the mean age at diagnosis, or the number or location of the involved parathyroid glands. Although routine calcium screening has identified significantly more cases of primary hyperparathyroidism, screening apparently does not enable diagnosis at an earlier stage.

The incidence of carcinoma in solitary "cold" thyroid nodules

Two hundred and three patients with single thyroid nodules were referred for radioactive scan of the thyroid. Solitary "cold" nodules were identified in 130 patients and 68 of these patients came to surgery. Of this group, 12 patients were found to have carcinoma. There was no obvious selection process which distinguished the 68 patients who underwent surgery from the 62 who did not. There is a significant risk of thyroid neoplasms occurring in patients with solitary "cold" nodules, and this is particularly true in patients under forty.

Diagnostic reliability of needle biopsy of the parietal pleura. A review of 272 biopsies

The clinical charts and histologic preparations from 245 patients who had pleural biopsies to evaluate pleural effusions of unknown etiology were reviewed. This represents an experience with 272 biopsies, as some patients underwent multiple biopsies. In 57 per cent of the cases of suspected or proven granulomatous disease involving the pleura, the pleural biopsy was positive. Similarly, in 48 per cent of the cases of suspected or proven pleural involvement by carcinoma, tumor was identified in the biopsy specimen. Only two false-positive diagnoses (one of granulomatous pleuritis and one of neoplastic disease) were made. The other 35 histologic diagnoses of granulomatous inflammation and 43 histologic diagnoses of carcinoma were verified. In this study, the authors found that the major limiting factor in establishing a diagnosis is the accuracy in random sampling of the parietal pleural surface. Thus, a negative pleural biopsy should not give the clinician a false sense of security.