James L. Mulshine

The American Association for Thoracic Surgery guidelines for lung cancer screening using low-dose computed tomography scans for lung cancer survivors and other high-risk groups

OBJECTIVE Lung cancer is the leading cause of cancer death in North America. Low-dose computed tomography screening can reduce lung cancer-specific mortality by 20%. METHOD The American Association for Thoracic Surgery created a multispecialty task force to create screening guidelines for groups at high risk of developing lung cancer and survivors of previous lung cancer. RESULTS The American Association for Thoracic Surgery guidelines call for annual lung cancer screening with low-dose computed tomography screening for North Americans from age 55 to 79 years with a 30 pack-year history of smoking. Long-term lung cancer survivors should have annual low-dose computed tomography to detect second primary lung cancer until the age of 79 years. Annual low-dose computed tomography lung cancer screening should be offered starting at age 50 years with a 20 pack-year history if there is an additional cumulative risk of developing lung cancer of 5% or greater over the following 5 years. Lung cancer screening requires participation by a subspecialty-qualified team. The American Association for Thoracic Surgery will continue engagement with other specialty societies to refine future screening guidelines. CONCLUSIONS The American Association for Thoracic Surgery provides specific guidelines for lung cancer screening in North America.

Randomized trial of neoadjuvant therapy for lung cancer: Interim analysis

The role of neoadjuvant chemotherapy in stage IIIa non-small cell lung cancer remains undefined. Since 1987, 27 patients with non-small cell lung cancer, all with histologically confirmed metastases to the ipsilateral mediastinal lymph nodes, have been enrolled in an ongoing prospective, randomized trial at our institution. Thirteen patients have been randomized to preoperative etoposide-platinum (EP) chemotherapy-surgery-postoperative EP, and 14 other patients have been randomized to surgery-postoperative mediastinal irradiation (SRT). Both groups are similar in sex, age, weight loss, tumor location, preoperative pulmonary function, physiologic grade, and tumor histology. Eight of the 13 EP patients have responded as evidenced by a 50% or greater radiographic tumor shrinkage after two cycles. Complete tumor and nodal resection rates were similar: 11/13 EP patients versus 12/14 SRT patients. There was no operative mortality for the 27 patients. Median potential follow-up is 29.9 months for the EP group and 34.9 months for the SRT group. Preliminary results suggest a trend toward increased survival time for the EP group (median, 28.7 months) versus the SRT group (median, 15.6 months) (p2 = 0.095). Eleven of 12 resected SRT patients have had recurrence versus 8 of 11 resected EP patients. Time to recurrence reveals no significant differences between the two groups but a trend toward increased disease-free interval in the EP group (12.7 months versus 5.8 months, EP versus SRT). This interim analysis demonstrates the feasibility of such a trial; however, despite the trends, definitive conclusions await further accrual and study maturation.

Growth control of lung cancer by interruption of 5-lipoxygenase-mediated growth factor signaling.

Signal transduction pathways shared by different autocrine growth factors may provide an efficient approach to accomplish clinically significant control of lung cancer growth. In this study, we demonstrate that two autocrine growth factors activate 5-lipoxygenase action of the arachidonic acid metabolic pathway in lung cancer cell lines. Both growth factors increased the production of 5(S)-hydrooxyeicosa-6E,8Z,11Z,14Z-tetraeno ic acid (5-HETE), a major early 5-lipoxygenase metabolic product. Exogenously added 5-HETE stimulated lung cancer cell growth in vitro. Inhibition of 5-lipoxygenase metabolism by selective antagonists resulted in significant growth reduction for a number of lung cancer cell lines. Primary clinical specimens and lung cancer cell lines express the message for the 5-lipoxygenase enzymes responsible for the generation of active metabolites. In vivo evaluation demonstrated that interruption of 5-lipoxygenase signaling resulted in enhanced levels of programmed cell death. These findings demonstrate that 5-lipoxygenase activation is involved with growth factor-mediated growth stimulation for lung cancer cell lines. Pharmacological intervention with lipoxygenase inhibitors may be an important new clinical strategy to regulate growth factor-dependent stages of lung carcinogenesis.

Insulin-like growth factor-I can mediate autocrine proliferation of human small cell lung cancer cell lines in vitro.

The effect of insulin-like growth factor I (IGF-I) on growth of small cell lung cancer (SCLC) cell lines was studied. Western blot analysis of whole cell lysates of cell lines NCI-H345 and NCI-N417 demonstrated the presence of a 16-kD band consistent with an IGF-I precursor molecule. Scatchard plot analysis of cell line NCI-H345 using 125I-labeled IGF-I demonstrated two high affinity specific binding sites (Kd 1.3 and 4.0 nM with maximal rate (Bmax) 200 and 500 fmol/mg protein, respectively). The exogenous addition of IGF-I, IGF-II, or insulin resulted in marked proliferation of human SCLC cells as evaluated using an in vitro growth assay. These peptides stimulated the growth of SCLC cell lines NCI-H82, NCI-H209, NCI-H345, and NCI-N417. The concentration of IGF-I producing maximal SCLC cell growth was 10-100-fold less than that of insulin or IGF-II, whereas the maximal growth stimulated by the optimal concentration of these peptides were similar. An MAb that specifically binds to the IGF-I receptor (but not to the insulin receptor) mediates a dose-dependent inhibition of cell growth in basal media as well as IGF-I, IGF-II, or insulin-supplemented media. The IGF-I receptor thus appears to be the common pathway for the mitogenic activity by IGF-I, IGF-II, and insulin for human SCLC cell lines. The demonstration of an IGF-I precursor molecule, specific IGF-I receptor binding, IGF-I-mediated growth stimulation, and inhibition of basal cell growth by an MAb to the IGF-I receptor suggests that an IGF-I-like molecule can function in vitro as an autocrine growth factor for human SCLC cell lines.

Prospective randomized comparison of high-dose and standard-dose etoposide and cisplatin chemotherapy in patients with extensive-stage small-cell lung cancer

PURPOSE We performed a prospective randomized clinical trial to determine whether higher doses of etoposide and cisplatin (EP) yield more complete responses or longer survival in small-cell lung cancer (SCLC) patients. PATIENTS AND METHODS Ninety patients with previously untreated extensive-stage SCLC fulfilled criteria for randomization to standard-dose versus high-dose EP. Another 25 patients at risk of excessive toxicity from high-dose treatment were given standard-dose therapy. During cycles 1 and 2 of EP, patients on standard-dose treatment received intravenous etoposide 80 mg/m2 on days 1 to 3 and cisplatin 80 mg/m2 on day 1 every 3 weeks; high-dose treatment consisted of etoposide 80 mg/m2 on days 1 to 5 and cisplatin 27 mg/m2 on days 1 to 5 every 3 weeks. All patients received standard-dose EP in cycles 3 and 4. In cycles 5 through 8, completely responding patients continued standard-dose EP; all other patients received either cyclophosphamide, doxorubicin, and vincristine, or (if possible) a combination drug program based on in vitro drug sensitivity testing of tumor-cell lines established from individual patients. RESULTS Despite 68% higher doses and a 46% higher dose-rate intensity actually given to patients randomized to receive high-dose relative to those randomized to receive standard-dose EP, complete response rates (23% v 22%; P = .99) and median survival durations (10.7 and 11.4 months, respectively; P = .68) were virtually identical. Complete responses occurred in 4% of patients and the median survival duration was 5.8 months in nonrandomized patients. Leukopenia (P < .0001), thrombocytopenia (P < .0001), febrile neutropenia (P = .01), and weight loss (P = .02) were significantly more common in patients randomized to receive high-dose compared with standard-dose EP. CONCLUSION No therapeutic benefits resulted from increasing planned doses by 67% for the first two cycles of EP in patients with extensive-stage SCLC. Higher doses were associated with substantially worse toxicities.

Five-lipoxygenase inhibitors can mediate apoptosis in human breast cancer cell lines through complex eicosanoid interactions.

Many arachidonic acid metabolites function in growth signaling for epithelial cells, and we previously reported the expression of the major arachidonic acid enzymes in human breast cancer cell lines. To evaluate the role of the 5‐lipoxygenase (5‐LO) pathway on breast cancer growth regulation, we exposed cells to insulinlike growth factor‐1 or transferrin, which increased the levels of the 5‐LO metabolite, 5(S)‐hydrooxyeicosa‐6E,8C,11Z,14Z‐tetraenoic acid (5‐HETE), by radioimmunoassay and high‐performance liquid chromatography. Addition of 5‐HETE to breast cancer cells resulted in growth stimulation, whereas selective biochemical inhibitors of 5‐LO reduced the levels of 5‐HETE and related metabolites. Application of 5‐LO or 5‐LO activating protein‐directed inhibitors, but not a cyclooxygenase inhibitor, reduced growth, increased apoptosis, down‐regulated bcl‐2, up‐regulated bax, and increased G1 arrest. Exposure of breast cancer cells to a 5‐LO inhibitor up‐regulated peroxisome proliferator‐activated receptor (PPAR)α and PPARγ expression, and these same cells were growth inhibited when exposed to relevant PPAR agonists. These results suggest that disruption of the 5‐LO signaling pathway mediates growth arrest and apoptosis in breast cancer cells. Additional experiments suggest that this involves the interplay of several factors, including the loss of growth stimulation by 5‐LO products, the induction of PPARγ, and the potential activation of PPARγ by interactions with shunted endoperoxides.

Lung cancer screening with low-dose computed tomography: A non-invasive diagnostic protocol for baseline lung nodules

BACKGROUND Indeterminate non-calcified lung nodules are frequent when low-dose spiral computed tomography (LD-CT) is used for lung cancer screening. We assessed the diagnostic utility of a non-invasive work-up protocol for nodules detected at baseline in volunteers enrolled in our single-centre screening trial, and followed for at least 1 year. METHODS 5201 high-risk volunteers, recruited over 1 year from October 2004, underwent baseline LD-CT; 4821 (93%) returned for the first repeat LD-CT. Nodules <or=5mm underwent repeat LD-CT at 1 year; nodules 5.1-8mm underwent LD-CT 3 months later; lesions >8mm received combined CT-positron emission tomography (CT-PET). A subset of nodules >8mm was studied by CT with contrast. Protocol failures were delayed diagnosis with disease progression beyond stage I, and negative surgical biopsy. RESULTS 2754 (53%) volunteers presented one or more non-calcified nodules. Ninety-two lung cancers were diagnosed: 55 at baseline and 37 at annual screening (66% stage I). Among the 37 incident cancers, 17 had a baseline nodule that remained stage I, 7 had a baseline nodule that progressed beyond stage I, and 13 presented a new malignant nodule. Baseline and annual cancers were 79 (1.5%) and 13 (0.2%), respectively. In 15 of 104 (14%) invasive diagnostic procedures, the lesion was benign. Sensitivity, and specificity were 91 and 99.7%, respectively, for the entire protocol; 88 and 93% for CT-PET; and 100 and 59% for CT with contrast. CONCLUSIONS The protocol limits invasive diagnostic procedures while few patients have diagnosis delay, supporting the feasibility of lung cancer screening in high-risk subjects by LD-CT. Nevertheless further optimization of the clinical management of screening-detected nodules is necessary.

Lipoxygenase Inhibitors Prevent Lung Carcinogenesis and Inhibit Non-Small Cell Lung Cancer Growth

The effects of lipoxygenase inhibitors were investigated using human lung cancer cell lines and A/J mice. By RT-PCR, 5-, 12-, and 15-lipoxygenase mRNA was detected in NSCLC cells. NDGA inhibited 5-LO activity in adenocarcinoma cell line NCI-H1264. Using an MTT assay, NDGA, MK591 and AA861 inhibited the growth of NSCLC cell lines tested with IC50 values of 3, 2, and 7 microM, respectively. Using a clonogenic assay, 10 microM NDGA significantly reduced NSCLC colony number. NDGA significantly slowed NSCLC xenograft growth in nude mice. When the tumors were excised and analyzed, nude mice treated with NDGA had significantly more apoptotic figures than did untreated tumors. A/J mice treated with urethane developed adenomas after 4 months and NDGA administration significantly reduced lung adenoma number. These data indicate that lipoxygenase inhibitors inhibit lung cancer growth and prevent lung carcinogenesis.

5-lipoxygenase inhibitors reduce PC-3 cell proliferation and initiate nonnecrotic cell death

Products of the arachidonic acid‐metabolizing enzyme, 5‐lipoxygenase, stimulate the growth of several cell types. Selective inhibitors of the enzyme, including SC41661A and MK886, reduce PC‐3 prostate cell proliferation. With continued culture, cells die, but the mode of death, necrotic or nonnecrotic, has not been established.

Lung cancer: current therapies and new targeted treatments

Lung cancer is the most frequent cause of cancer-related deaths worldwide. Every year, 1·8 million people are diagnosed with lung cancer, and 1·6 million people die as a result of the disease. 5-year survival rates vary from 4-17% depending on stage and regional differences. In this Seminar, we discuss existing treatment for patients with lung cancer and the promise of precision medicine, with special emphasis on new targeted therapies. Some subgroups, eg-patients with poor performance status and elderly patients-are not specifically addressed, because these groups require special treatment considerations and no frameworks have been established in terms of new targeted therapies. We discuss prevention and early detection of lung cancer with an emphasis on lung cancer screening. Although we acknowledge the importance of smoking prevention and cessation, this is a large topic beyond the scope of this Seminar.