Somatostatin and the lung

Effect of Octreotide on Neuroenolase Levels in Patients with Small Cell Lung Cancer

Aims and Background

The somatostatin analog octreotide has an antiproliferative effect on small cell lung cancer lines in vitro and in experimental xenograft transplantation systems in vivo. Thus it is worth investigating octreotide activity in the clinical setting.

Methods

We studied the effect of octreotide (200 μg three times a day subcutaneously for seven days) on serum levels of the tumor marker neuroenolase in 13 patients with small cell lung cancer.

Results

A decrease in neuroenolase levels was observed at day 7 during octreotide treatment, with a mean ± SD of 32.6 ± 42.0 ng/ml compared to basal values of 44.4 ± 57.7 ng/ml and to washout values of 50.3 ± 65.7 ng/ml ( P < 0.03).

Conclusions

Our results indicate that octreotide is effective in reducing neuroenolase levels in small cell lung cancer patients. These data suggest a possible role for octreotide in the treatment of this kind of tumor.

Somatostatin Analog Therapy in Small Cell Lung Cancer

Chemotherapy represents the cornerstone of treatment for patients with small cell lung cancer (SCLC); however, standard therapy has reached a plateau in improving patient survival with overall disappointing results. The demonstration that SCLC expresses neuroendocrine markers, such as somatostatin (SST) receptors, has led to use SST analogs or radiolabeled SST analogs in the treatment of SCLC patients. In the current review, we would focus on the possible role of SST analogs in SCLC.

The usefulness of combined diagnostic CT and (99m)Tc-octreotide somatostatin receptor SPECT/CT imaging on pulmonary nodule characterization in patients

The objective of this study was to evaluate the clinical value of combination of diagnostic computed tomography (CT) and somatostatin receptor imaging with (99m)Tc-octreotide acetate SPECT/CT in differentiation of benign pulmonary nodules from cancers.

METHODS

This was a retrospective study, 29 patients with suspected pulmonary neoplasm underwent diagnostic CT and (99m)Tc-octreotide SPECT/CT scans, and the tumor-to-normal tissue tracer value (T/N) for (99m)Tc-octreotide was measured. Diagnosis was confirmed by histological analysis.

RESULTS

Eighteen of the 29 patients included in this study had lung cancer: 2 with small cell lung cancer and 16 with nonsmall cell lung cancer. The other 11 patients had benign lung lesions: 5 with tuberculosis, 4 with nontuberculosis infection, 1 with hematoma, and 1 with fibroma. (99m)Tc-octreotide uptake (expressed as mean T/N±SD) was significantly higher in lung cancers (2.58±0.91) than benign lesions (1.38±0.79) (p=0.002). Specificity for pulmonary malignant nodule diagnosis was 63.6% for diagnostic CT, 72.7% for somatostatin receptor SPECT/CT imaging, and 81.8% for the combined use of diagnostic CT and somatostatin receptor SPECT/CT imaging.

CONCLUSION

Somatostatin receptor imaging with (99m)Tc-octreotide SPECT/CT is useful for the differentiation of benign pulmonary nodules from lung cancers, the combination of diagnostic CT and (99m)Tc-octreotide SPECT/CT further increases the specificity of malignant pulmonary nodule detection.

Simultaneous occurrence of typical carcinoid and non-small-cell lung cancer in the same lung lobe: value of nuclear medicine

The present report demonstrates the usefulness of nuclear medicine in differentiating different pulmonary tumors. A 79-year-old woman presented with a suspicious peripherally located lesion of the right lower lobe in the costophrenic angle. During bronchoscopic evaluation, a centrally located intrabronchial lesion was found, which was positive on a subsequent In-111 octreotide examination. The histologic examination of this central lesion confirmed a typical bronchial carcinoid. The FDG PET examination revealed a high uptake just in the peripherally located lesion, which was then confirmed to be non-small-cell lung cancer. This is the first report of nuclear medicine methods evaluating simultaneous occurrence of a typical bronchial carcinoid and a non-small-cell lung cancer in the same lung lobe.

Characterization of radiologically indeterminate lung lesions: 99mTc-depreotide SPECT versus 18F-FDG PET

AIM

To evaluate the diagnostic accuracy of 99m Tc-depreotide vs PET-18FDG scans in patients with suspicion of lung cancer.

MATERIAL AND METHODS

Prospective study in 29 patients (age: 38-80 years) diagnosed of inderteminate lung lesions. Diagnosis was established by histology based on samples of surgical resection, fine needle aspiration (FNA) or broncoalveolar lavage (BAL). Within a maximum of 10 days, without pre-established fixed order the following exams were performed: 1) Whole body and chest SPECT-CT with Tc-depreótide (DEP-SPECT) and 2) PET-CT study with F-FDG (PET-FDG). Every exam was evaluated by Nuclear Medicine especialist blinded to patient data.

RESULT

Malignancy was confirmed in 20 patients. PET-FDG was positive in all cases. DEP-SPECT was positive in 17 and falselly negative in 3, one carcinoid tumor, one undifferentiated non-small cell adenocarcinoma, and a moderately differentiated adenocarcinoma. In the remaining 9 patients benignancy was confirmed; both studies were normal in 8 and falselly positive in one case of non-specific inflammatory lung process. In 9 out of the 20 cases with malignancy extrapulmonar uptake was seen, with a total number of 19 lesions. In two cases the extrapulmonar uptake were non ganglionar metastasis (bone and adrenal) and in 7 due to mediastinic ganglionar involvement. ROC analysis using peak SUV FDG (cut-off point of 3.5) uptake and target/background depreotide uptake (cut-off point of 1.3) provided, sensitivity and specificity values of 95% and 89% of 84% and 88% for PET and SPECT respectively. It does not exist statistically significant differences between both methods (Z-test SPSS). In summary, FDG-PET has a greater sensitivity and diagnostic accuracy for assessing malignancy of indeterminate lung lesions, and for detection of extrapulmonary involvement, DEP-SPECT represents a good diagnostic alternative for centers where PET is not available.

Efficiency of 18F-FDG and 99mTc-depreotide SPECT in the diagnosis of malignancy of solitary pulmonary nodules

PURPOSE

The purpose of the study was to compare ( 18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) and ( 99m)Tc-depreotide single-photon emission computed tomography (SPECT) in the diagnosis of malignancy of solitary pulmonary nodules (SPNs).

METHODS

Twenty-eight patients without any history of cancer and presenting an SPN (0.8-3 cm in size) underwent FDG PET and depreotide SPECT. Depreotide SPECT and FDG PET were performed on a double-head gamma camera and a dedicated PET scanner respectively. Twenty-five out of 28 lesions were removed by thoracotomy or assessed by biopsy (n=1) and histologically examined. A strategy of serial CT scanning was adopted in the three remaining patients.

RESULTS

Histological findings revealed 18 malignant nodules and seven benign lesions. Stability over a 2-year period indicated a benign process in the remaining three cases. Both techniques yielded true positive results in 15 of the 18 cancers. FDG PET identified two additional adenocarcinomas not detected by depreotide SPECT. A carcinoid tumour not visualised on FDG PET was identified by depreotide SPECT. Seven of the ten benign lesions did not reveal tracer uptake on either depreotide SPECT or FDG PET. Both techniques showed false positive results for the same two lesions. One more false positive was seen on FDG PET. FDG PET and depreotide SPECT had a sensitivity of 94.4% and 88.9% respectively; this difference was not significant. In our experience, depreotide SPECT and FDG PET are equally sensitive (92.3%) for large (>1.5 cm) and equally specific (85.7%) for small (up to 1.5 cm) SPNs suspicious for malignancy.

CONCLUSION

This study showed( 18)F-FDG PET to be more sensitive than ( 99m)Tc-depreotide SPECT in the diagnosis of malignancy of SPNs. However, the combination of both techniques may provide additional accuracy.

Imaging of regional lymph node metastases with 99mTc-depreotide in patients with lung cancer

PURPOSE

The aim of this study was to evaluate the clinical usefulness of scintigraphy with 99mTc-depreotide in the assessment of loco-regional nodal spread in patients with suspected lung cancer in comparison with computed tomography (CT).

METHODS

Eighty-six patients were investigated with single-photon emission computed tomography (SPECT) of the thorax after i.v. injection of 740 MBq 99mTc-depreotide. The results were evaluated in conjunction with a thoracic CT scan in all 86 patients with 204 lymph node stations. The scintigraphic results were correlated with cytological (38), histological (20) or clinical-radiological (146) findings and compared with CT. The quantitative evaluation of depreotide uptake was performed on 48 cytologically or histologically verified nodal stations from 28 patients by SPECT using region of interest analysis with four different reference regions.

RESULTS

99mTc-depreotide scintigraphy for all 204 investigated lymph node stations had a sensitivity of 99% and a negative predictive value of 98% in determining lymph node involvement. Scintigraphy and CT showed the same level of accuracy, 76.4%. CT findings had a higher positive predictive value but a lower negative predictive value compared to 99mTc-depreotide scintigraphy. The quantitative evaluation of depreotide uptake in lymph nodes using vertebra as a reference region showed that a cut-off level of 0.56 excludes malignant involvement of lymph nodes, while a cut-off level of 1.66 excludes benign disease in lymph nodes. About 73% of all investigated lymph node stations showed uptake values between these cut-off levels.

CONCLUSION

Absence of 99mTc-depreotide uptake on scintigraphic imaging can exclude regional lymph node involvement with a high degree of probability and may be useful in clinical practice. The quantitative evaluation of depreotide uptake in regional lymph nodes did not increase the diagnostic accuracy of the method in general but did elucidate the lymph node status in some patients.

The Utility of 99m Tc Depreotide Compared With F-18 Fluorodeoxyglucose Positron Emission Tomography and Surgical Staging in Patients With Suspected Non-small Cell Lung Cancer

STUDY OBJECTIVES

The findings from conventional imaging modalities, such as chest CT, are frequently unreliable in patients with lung cancer. This study was designed to compare the relative diagnostic accuracies and utility of the two most widely used functional imaging examinations, F-18-2-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and (99m)Tc depreotide scintigraphy, for the diagnosis and staging of lung cancer.

DESIGN

Prospective, experimental investigation.

SETTING

Academic medical center.

PATIENTS

One hundred sixty-six subjects with suspected lung cancer were enrolled in the study.

INTERVENTIONS

Whole-body and single-photon emission CT imaging of the chest was performed after IV administration of (99m)Tc depreotide. Attenuation-corrected FDG PET imaging was performed after IV administration of FDG. Image findings were compared with the biopsy results or clinical follow-up.

MEASUREMENTS AND RESULTS

In 157 subjects with evaluable lung lesions, the sensitivities and specificities for detecting malignant disease (95% confidence intervals) of FDG PET are 96% (90 to 98%) and 71% (54 to 85%), and of (99m)Tc depreotide are 94% (88 to 98%) and 51% (34 to 68%). In the 139 subjects with available complete staging data, FDG PET correctly staged 76 of 139 patients (55%), and (99m)Tc depreotide correctly staged 63 of 139 patients (45%).

CONCLUSIONS

The sensitivity for detection of lung cancer in the primary lesion is equally high for FDG PET and (99m)Tc depreotide. The specificity is superior for FDG PET. The staging accuracy of FDG PET and (99m)Tc depreotide is similar, but when read with the chest CT neither scintigraphic examination is sufficiently accurate to stage patients with non-small cell lung cancer.

Accumulation of Tc-99m depreotide (NeoSpect) in axillary sweat glands

Tc-99m depreotide (NeoSpect) is a radiolabeled somatostatin analog introduced recently for scintigraphic imaging of patients with lung cancer. Eighteen patients were examined 2 to 4 hours after administration of 740 MBq mCi Tc-99m depreotide. In 13 patients (72.2%) bilateral symmetric activity corresponding to the large, deep apocrine sweat glands of the axillae was present. This observation is clinically relevant regardless of its reason or mechanism. It is important to be aware of this reason for activity in the axillae when assessing lymph node involvement not only in patients with lung cancer but also in breast cancer patients using scintigraphy with Tc-99m depreotide.

Neuroendocrine markers in adenocarcinomas: an investigation of 356 cases

AIM: To investigate the incidence of neuroendocrine (NE) cells and their hormone products in adenocarcinomas and evaluate their significance in clinical pathology and prognosis.

METHODS: By using tissue sectioning and immunocyto-chemistry, 356 cases of adenocarcinomas were studied to examine the presence of chromorgranin and polypeptide hormones in adenocarcinoma samples from our hospital.

RESULTS: The positive rate of NE cells and hormone products was 41.5% (54/130) and 59.3% (32/54), respectively in large intestinal adenocarcinoma cases; 39.6% (38/96) and 36.8% (14/38), respectively in gastric cancer cases; 38.1% (8/21) and 50.0% (4/8), respectively in prostatic cancer cases; 21.0% (17/81) and 17.6% (3/17), respectively in breasr cancer cases; 17.9% (5/28) and 60.0% (3/5), respectively in pancreatic cancer cases. Among carcinomas of large intestine, pancreas and breast, the highly differentiated NE cell numbers were higher than the poorly differentiated NE cell numbers; while the gastric carcinoma cases had more poorly differentiated NE cells than highly differentiated NE cells. The higher detection rate of NE cells and their hormone products, the higher 5-year survival rate among the large intestine cancer cases.

CONCLUSION: Close correlation was observed between NE cells and their hormone products with the cancer differentiations. For colorectal carcinomas, there is a close correlation of the presence of NE cells and their hormone products with the tumor staging and prognosis.

Peptide and antibody imaging in lung cancer

Noninvasive differentiation of malignant from benign pulmonary nodules and the staging of lung cancer are major challenges and opportunities for radionuclide imaging. Despite the performance of (18)F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging in addressing these needs, access to PET imaging in the United States and other countries is still limited for many people. Furthermore, FDG-PET imaging has left room for improvement. Thus, the need for addressing these diagnostic issues exists for a significant portion of the population of the United States and the rest of the world. Labeled antibody and peptide single-photon emission computed tomography imaging offers a reasonable alternative for these indications and comes close to FDG-PET imaging in performance, along with a lower cost when all overhead is included. Although these tracers have a high sensitivity in the diagnosis of primary and metastatic tumors, their specificity is limited by uptake in granulomatous disease, similar to that of FDG-PET. Regardless of these daunting challenges, radiolabeled antibody and peptide imaging deserves a recognized role in the clinical management of lung cancer.

Positron emission tomography in lung cancer

Carcinoma of the lung is one of the most frequent malignancies and a major cause of mortality. The use of positron emission tomography (PET) has been extensively investigated in patients with carcinoma of the lung and has established clinical utility and cost-effectiveness in characterization of solitary pulmonary nodules and preoperative staging of carcinoma of the lung. Evolving applications in carcinoma of the lung include detection of recurrence, assessment of treatment response, radiotherapy planning, and prognosis. In addition, there is developing interest in combined anatomic/metabolic imaging and new tracer techniques, in particular gene expression imaging. This review aims to present existing data supporting the use of PET in carcinoma of the lung and to explore the evolving indications and future prospects of PET and lung cancer.

Soft tissue metastases and lung cancer recurrence detected by Tc-99m depreotide scintigraphy

A 63-year-old woman with previously treated stage I lung cancer was reexamined 5 years later for recurrence. A conventional work-up using computed tomographic scanning and transbronchial biopsy showed nothing abnormal. A Tc-99m depreotide scan, however, led to a noninvasive diagnosis of lung cancer recurrence with metastases, and it directed a noninvasive tissue diagnosis.

A multicenter trial with a somatostatin analog (99m)Tc depreotide in the evaluation of solitary pulmonary nodules

OBJECTIVE

The affinity of various malignant neoplasms including small cell and non-small cell lung cancer for peptide analogs of somatostatin has been well documented. Depreotide is such an analog and can be complexed with technetium-99m ((99m)Tc depreotide) for optimal imaging properties. Using this radiopharmaceutical, solitary pulmonary nodules (SPN) were previously evaluated in a successful phase II/III trial. The results of the larger multicenter phase III study using (99m)Tc depreotide to differentiate malignant and benign etiologies in SPN are now presented.

METHODS

Patients with SPN </= 6 cm on chest radiograph were referred for evaluation. One hundred fourteen individuals who had an absence of a benign pattern of calcification on CT scan, age > 30 years, and no demonstrable radiographic stability for the prior 2 years were studied. All underwent single-photon emission CT (SPECT) with (99m)Tc depreotide and subsequent tissue histologic examination. Three nuclear medicine specialists blinded to histologic findings examined the SPECT images and scored them as positive or negative based on the presence or absence of activity in the radiographic region of the SPN. The final result was determined by the majority score, which was then compared with the histologic result.

RESULTS

Of the 114 individuals studied, 88 had a histologic result compatible with malignant neoplasm. (99m)Tc depreotide scintigraphy correctly identified 85 of this group, with three false-negative determinations compared with histology. There were seven false-positive determinations, including six granulomas and one hamartoma. (99m)Tc depreotide scintigraphy correctly excluded malignancy in 19 of 26 patients with benign histologic findings. The sensitivity of this method was 96.6% with a specificity of 73.1%.

CONCLUSION

(99m)Tc depreotide scintigraphy is a safe and useful method for the noninvasive evaluation of SPN with a sensitivity and accuracy comparable to that reported for fluorine-18 fluorodeoxyglucose positron emission tomography.

The utility of a somatostatin-type receptor binding peptide radiopharmaceutical (P829) in the evaluation of solitary pulmonary nodules

OBJECTIVE

Many neoplasms including small cell cancers more densely express somatostatin-type receptors or more avidly bind somatostatin than granulomatous and other nonmalignant processes. While non-small cell neoplasms of the lung have not yet been shown to demonstrate this receptor expression, previous studies have documented non-small cell lung cancer detection with somatostatin analog scintigraphy. This phenomenon can be conceivably exploited utilizing technetium Tc-99m P829 (P829), a unique low molecular weight somatostatin-type receptor binding polypeptide radiopharmaceutical. The objective of this study was to determine the ability of P829 scintigraphy to noninvasively differentiate malignant and nonmalignant solitary pulmonary nodules (SPNs).

METHODS

The radiopharmaceutical technetium 99mTc-P829 was utilized for scintigraphy including single photon emission computed tomography. Thirty individuals with indeterminate SPNs of > or = 1 cm and significant risk factors for primary lung cancer were identified and underwent P829 scintigraphy. Tissue diagnosis was then established by transthoracic needle biopsy specimens.

RESULTS

Fourteen subjects demonstrated abnormal P829 scans in the region of the radiographic abnormality. Twelve of this group had biopsy specimens revealing neoplasia. Two subjects with necrotizing granuloma on biopsy specimen had abnormal P829 scans in the region of the nodule. Sixteen subjects had no abnormal P829 tracer uptake in the region of the nodule. Fourteen subjects had benign diagnoses on biopsy specimens. One member of this group with a non-diagnostic biopsy specimen refused thoracotomy and remains radiographically stable at 24 months of follow-up. One subject with a squamous cell carcinoma demonstrated no P829 activity in the region of the nodule. The specificity of P829 scintigraphy based on transthoracic needle biopsy specimen was 88%. The sensitivity was 93%. P829 scintigraphy correctly identified or excluded malignancy in 27 of 30 subjects.

CONCLUSIONS

P829 scintigraphy reliably identified or excluded malignancy in radiographically indeterminate solitary pulmonary nodules. The sensitivity and specificity compared favorably with the reported results of F-18 fluorodeoxyglucose positron emission tomographic imaging.

Characterization of methadone receptor subtypes present in human brain and lung tissues

In addition to their use in pain control, opioids can function as regulators of tumor cell growth. We have found that the therapeutic opioid, methadone, significantly inhibits the in vitro and in vivo growth of human lung cancer cells, and this effect appears to be mediated by specific, high affinity, non-conventional opioid binding sites. The present study indicates the existence of multiple subtypes of binding sites mediating the peripheral and central nervous system actions of this drug. Pharmacological and biochemical characterizations of the methadone binding sites expressed in human brain and normal lung tissues indicate that these sites are distinct from each other and from other opioid receptor types present on human and rat brain membranes, as well as those expressed in human lung cancer cells. The identification of distinct methadone receptor types in the different tissues could lead to the development of more selective and less toxic drugs targeted toward the tumor cells.

A somatostatin analogue inhibits MAP kinase activation and cell proliferation in human neuroblastoma and in human small cell lung carcinoma cell lines

Somatostatin possesses antisecretory and antiproliferative activity on some human tumors. We herein report that, in a human neuroblastoma cell line, the somatostatin analogue BIM 23014 inhibited mitogen-activated protein (MAP) kinase activity stimulated by either insulin-like growth factor-1, whose receptor bears a tyrosine kinase, or carbachol, which acts at a G-protein coupled receptor. In a human small cell lung carcinoma line BIM inhibited serum-stimulated MAP kinase activation. These inhibitory actions occur in a dose range quite similar to that observed for suppression of proliferation induced by the analogue in the same cell lines. The decrease in cAMP elicited by the analogue in the two cell lines is not responsible for its inhibitory action on MAP kinase and cell growth. Moreover, the analogue did not modify intracellular [Ca2+] and pH. An involvement of a phosphatase activity is suggested.

A metastatic neuroendocrine anaplastic small cell tumor in a patient with multiple endocrine neoplasia type 1 syndrome. Assessment of disease status and response to doxorubicin, cyclophosphamide, etoposide chemotherapy through scintigraphic imaging with 111In-pentetreotide

Extrapulmonary small cell and small cell neuroendocrine tumors of unknown primary site are, in general, aggressive neoplasms with a short median survival. Like small cell lung cancer (SCLC), they often are responsive to chemotherapy and radiotherapy. Small cell lung cancer and well differentiated neuroendocrine carcinomas of the gastrointestinal tract and pancreas tend to express somatostatin receptors. These tumors may be localized in patients by scintigraphic imaging using radiolabeled somatostatin analogues. A patient with anaplastic neuroendocrine small cell tumor arising on a background of multiple endocrine neoplasia type 1 syndrome is reported. The patient had a known large pancreatic gastrinoma and previously treated parathyroid adenopathy. At presentation, there was small cell cancer throughout the liver and skeleton. Imaging with a radiolabeled somatostatin analogue, 111In-pentetreotide (Mallinckrodt Medical B. V., Petten, Holland), revealed all sites of disease detected by routine biochemical and radiologic methods. After six cycles of chemotherapy with doxorubicin, cyclophosphamide, and etoposide, there was almost complete clearance of the metastatic disease. 111In-pentetreotide scintigraphy revealed uptake consistent with small areas of residual disease in the liver, the abdomen (in mesenteric lymph nodes), and posterior thorax (in a rib). The primary gastrinoma present before the onset of the anaplastic small cell cancer showed no evidence of response to the treatment. The patient remained well for 1 year and then relapsed with brain, lung, liver, and skeletal metastases. Despite an initial response to salvage radiotherapy and chemotherapy with carboplatin and dacarbazine, the patient died 6 months later.

Somatostatin receptor expression in lung cancer

Experimental evidence suggests that somatostatin analogues may have a role to play in the management of lung tumours. We evaluated membrane preparations of nine small cell lung cancer (SCLC) cell lines and of tumour samples from 3 patients with non-small cell lung cancer (NSCLC), 1 patient with an atypical carcinoid and another with a bronchial carcinoid for the presence of specific binding sites for RC-160, a potent growth inhibitory octapeptide analogue of somatostatin. Specific binding was noted on six of nine SCLC lines. Radio-receptor assay on the cell line NCI H 69 showed evidence of two specific binding sites for RC-160, one with high affinity and the other with low affinity. Binding sites were also found on all five tumour samples. Scatchard analysis indicated the presence of a single class of receptors with high affinity in each case. Histological assessment of the resected specimens before binding assay showed them to be comprised of tumour cells and necrotic tissue, stroma and/or inflammatory cells. Therefore, the specific binding of RC-160 may be to tissues other than the tumour cells. In 3 patients, from whom the tumour samples were obtained, radiolabelled somatostatin analogue scintigraphy using [111In] pentetreotide was performed prior to surgery. In all cases, the radiolabel localised the disease. This study demonstrates the presence of specific binding sites for RC-160 in SCLC. Furthermore, the detection of specific binding in vitro and in vivo in NSCLC and intrapulmonary carcinoids demonstrates that these tumours contain cells which express specific binding sites for somatostatin. These results suggest that RC-160 may have a role to play as a therapeutic agent in lung cancer.