The ying and yang of idebenone: Not too little, not too much - cell death in NQO1 deficient cells and the mouse retina

Idebenone has recently been investigated as a drug therapy for Leber's hereditary optic neuropathy (LHON), a rare genetic mitochondrial disease that causes rapid and progressive bilateral vision loss. Although several studies have shown that idebenone can promote vision recovery in patients with LHON, the evidence for the efficacy of idebenone is still limited. Idebenone failed to demonstrate superiority over placebo in the primary end-points of the only published randomised, double-blind, placebo-controlled trial. There appears to be a patient-specific response to idebenone with high variability in therapeutic outcomes. A recent study suggested that the cytosolic enzyme NAD(P)H: quinone acceptor oxidoreductase (NQO1) is the major enzyme involved in the activation of idebenone, and the beneficial effects of idebenone are dependent on the expression of NQO1. Here, we confirm the NQO1-dependent activity of idebenone, but we also show, for the first time, that the cytotoxicity of idebenone is linked to cellular expression of NQO1. Upon idebenone administration, cells deficient in NQO1 show a marked decrease in viability in comparison to NQO1 expressing cells, with idebenone causing ROS production and deleterious effects on ATP levels and cell viability. In addition, our data highlights that only cells expressing NQO1 can significantly activate idebenone, indicating that other proposed metabolic activation pathways, such as complex II and glycerol-3-phosphate dehydrogenase, do not play a significant role in idebenone activation. Furthermore, we provide evidence of idebenone-induced toxicity in the retina ex-vivo, which can be explained by the variation of NQO1 expression between different cell types in the mouse retina. Idebenone mediated cell rescue in the rotenone ex vivo model also indicated that this drug has a narrow therapeutic window. These findings will help to guide the development of future therapies and drug delivery strategies including intra-ocular administration. The specific dependence of idebenone activity on NQO1 may also explain the variation in patient outcomes in clinical trials.

Abstract P4-15-06: Low dose tamoxifen lowers recurrences after mastectomy for in situ neoplasia. Ten-year results of a monoinstitutional study

There is no agreement upon the need of a preventive treatment after breast mastectomy for in situ neoplasia. Low-dose tamoxifen (5 mg/day) has comparable antiproliferative effect than the standard dose of 20 mg/day in biomarker trials and has been shown to halve ipsilateral recurrence in a large cohort of postmenopausal ER positive DCIS treated with breast conserving surgery (Guerrieri-Gonzaga et al., Int J Cancer 2016).

Here we investigated the effect of low dose tamoxifen in patients treated with mastectomy for an in situ neoplasia and followed-up in a single Institution for a median of 10 years.

Our cohort consists of 404 consecutive premenopausal (n=281) or postmenopausal (n=123) women who underwent unilateral mastectomy at the European Institute of Oncology (IEO), with or without nipple preservation, between 1996 and 2011. Patients had a diagnosis of pure LCIS (n=12) or ER positive (ER>1%) DCIS (n=363) or both (n=29) and were treated with tamoxifen 5 mg/day (n=162) or no treatment (n=242) upon medical judgment, patient preference and/or clinical trial assignment. The main subject and tumor characteristics are reported in table 1.

Patient and tumor characteristics No tam (n=242)Low dose tam (n=162)P-valueMedian age, years (IQR)46 (41, 54)47 (42, 51)0.65Premenopausal status (n, %)160 (66)121 (75)0.07Median BMI (kg/m2, IQR)22 (20, 25)22 (20, 24)0.7Breast cancer family history (%)29320.44Histology (LCIS, DCIS, both; %)4/92/42/86/120.01Grading (G1,G2,G3;%)11/59/2918/61/200.04Median ER (%, IQR)90 (70, 95)90 (80, 95)0.005Median PgR (%, IQR)40 (5, 80)68 (25, 90)0.0002Median Ki67 (%, IQR)15 (10, 23)14 (10, 20)0.03Radiotherapy (n, %)95 (39)76 (47)0.13

After a median follow-up of 10 years (range 4-21 years) and a median low dose tamoxifen treatment of 4.9 years (IQR 2.7, 5.0), a total of 85 events were observed (28 in situ, 40 invasive breast cancers, 3 metastatic diseases, 12 other primary cancers, 2 deaths). A total of 36 ipsilateral breast events (23 versus 13 in the no tam versus tam group, respectively), 32 contralateral breast events (22 versus 10 in the no tam versus tam, respectively) and 17 other events (11 versus 6 in the no tam versus tam, respectively) occurred. Overall, eleven deaths (3%) occurred and no endometrial cancers were observed. A time-dependent competing risk model was applied for tamoxifen use and we have shown that low-dose tamoxifen was associated with a 48% reduction on all breast events (adjusted HR=0.52, 95% CI: 0.31–0.88, p=0.01), adjusting for radiotherapy and age.

Although limited by the observational nature of the study, we show for the first time that treatment with low dose tamoxifen is effective and safe in women who underwent mastectomy for non-invasive breast neoplasms and should be taken into consideration as a risk reduction strategy for premenopausal and postmenopausal women with breast intraepithelial neoplasia.

Citation Format: Guerrieri-Gonzaga A, Gandini S, Serrano D, Lazzeroni M, Pruneri G, Varricchio C, Cazzaniga M, Leonardi MC, Galimberti V, Viale G, De Censi A, Bonanni B. Low dose tamoxifen lowers recurrences after mastectomy for in situ neoplasia. Ten-year results of a monoinstitutional study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-15-06.

Tailoring treatment for ductal intraepithelial neoplasia of the breast according to Ki-67 and molecular phenotype

Background:

The post-surgical management of ductal intraepithelial neoplasia (DIN) of the breast is still a dilemma. Ki-67 labelling index (LI) has been proposed as an independent predictive and prognostic factor in early breast cancer.

Methods:

The prognostic and predictive roles of Ki-67 LI were evaluated with a multivariable Cox regression model in a cohort of 1171 consecutive patients operated for DIN in a single institution from 1997 to 2007.

Results:

Radiotherapy (RT) was protective in subjects with DIN with Ki-67 LI ≥14%, whereas no evidence of benefit was seen for Ki-67 LI <14%, irrespective of nuclear grade and presence of necrosis. Notably, the higher the Ki-67 LI, the stronger the effect of RT (P-interaction <0.01). Hormonal therapy (HT) was effective in both Luminal A (adjusted hazard ratio (HR)=0.56 (95% CI, 0.33–0.97)) and Luminal B/Her2neg DIN (HR 0.51 (95% CI, 0.27–0.95)).

Conclusion:

Our data suggest that Ki-67 LI may be a useful prognostic and predictive adjunct in DIN patients. The Ki-67 LI of 14% could be a potential cutoff for better categorising this population of women at increased risk for breast cancer and in which adjuvant treatment (RT, HT) should be differently addressed, independent of histological grade and presence of necrosis.

Abstract PD04-07: The Ki-67 labeling index predicts the risk of recurrence of DIN patients treated with radiotherapy following breast conserving surgery

Purpose: To investigate the prognostic relevance of Ki-67 labeling index (LI) in patients with Ductal Intraepithelial Neoplasia (DIN) of the breast.

Patients and Methods: From January 1997 to December 2007, histological samples and clinical data of 1,171 consecutive patients operated for DIN in a single institution were collected. The study was performed in accordance with the REMARK criteria. The independent prognostic role of Ki-67 LI was evaluated with a multivariable Cox regression model. A restricted cubic splines model was used to evaluate the prognostic role of Ki-67 LI as a continuous variable.

Results: Overall, median age was 52 years (range 23–88), median Ki-67 LI 15% (range 1–80) and median follow-up 86 months (range 1–192). Overall, 549 (46.9%) women were premenopausal at the time of diagnosis. A total of 872 (74.5%) patients underwent breast conservative surgery (BCS). Whole breast radiotherapy (RT) was administered to 356 patients, and 506 patients received low dose tamoxifen (HT) (20mg/week or 5 mg/day). Histologically, most of the cases had a prevalent solid or cribriform pattern (75%), were DIN1c and DIN2 (80%), ER+ (80%), and showed a high (≥14%) Ki-67 LI (54%). The prevalence of the immunohistochemically defined subtypes was 39.5% for Luminal (Lum) A, 22.8% for LumB/Her-2−, 18.2% for LumB/Her2+, 15.8% for Her-2+, and 3.7% for Triple Negative. Overall, the rate of invasive and in situ recurrences (5-year cumulative incidence) was 10.7%. Firstly, we analyzed the role of RT according to Ki-67 LI as a continuous variable in DIN2/DIN3 patients after BCS. The curve and interaction model was adjusted for menopause, BMI, Her-2 and ER status, histological grade, presence of necrosis and microcalcifications, and HT. RT was protective in subjects with DIN with Ki-67 LI ≥14%, while no evidence of effect was seen for Ki-67 LI &lt;14%. Notably, the higher the Ki-67 LI, the stronger the effect of RT (P-value for the interaction between RT and Ki-67 LI &lt;0.01). Accordingly, RT was effective in all DIN subtypes with the exception of LumA. The adjusted HRRT vs No RT for LumB/Her2−, LumB/Her2+, and Her2 subtypes was 0.20 (95 % CI, 0.08–0.48), 0.44 (95 % CI, 0.16–1.20), and 0.15 (95 % CI, 0.04–0.50), respectively. The HRRT vs No RT for Triple Negative subtype was 0.40 (95 % CI, 0.07–2.41) and was not adjusted because of the sparse number of events. Finally, we focused the analysis on DIN2 patients stratified by Ki-67 LI. Again, after adjustment for menopause, surgical margins, presence of necrosis, microcalcifications, and HT, RT was not effective in DIN2 patients with Ki-67 LI &lt;14% [HRRT vs No RT: 1.15 (95 % CI 0.47–2.80)]. On the contrary, DIN2 patients with a Ki-67 LI ≥14% mostly benefit of RT in terms of ipsilateral recurrence[HRRT vs No RT: 0.18 (95% CI 0.07–0.46)]. Low dose tamoxifen was effective in either LumA [adjusted HRHT vs No HT: 0.56 (95 % CI 0.33–0.97)] and LumB/HER2− DIN [HRHT vs No HT: 0.51 (95 % CI 0.27–0.95)], but not in LumB/Her2+ [HRHT vs No HT: 1.06 (95 % CI 0.56–2.05).

Conclusion: Our data suggest that Ki-67 LI may be a useful prognostic and predictive adjunct in DIN patients.

Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr PD04-07.

Low-Dose Tamoxifen for the Treatment of Breast Ductal Intraepithelial Neoplasia: Results of a Large Observational Study

Background: The cost-benefit ratio of tamoxifen for breast ductal intraepithelial neoplasia (DIN) is unclear. Since low-dose tamoxifen showed a favorable safety profile and modulation of breast cancer biomarkers in phase II trials, we analyzed a large mono-institutional cohort of women with DIN treated with low-dose tamoxifen or no systemic treatment.Material and Methods: A total of 309 patients with ER positive DIN received either tamoxifen 5 mg/day or 20 mg/week, as part of clinical trials or institutional guidelines and were compared with 371 patients who received no systemic treatment after surgery with or without radiotherapy due to personal preference, allocation to placebo or contraindication to tamoxifen.Results: The 5-year cumulative incidence of recurrence was 14.5% (95% CI, 11.9-17.5), with a negative trend according to age. Women with ER/PgR &gt;50% DIN who were untreated had a higher incidence of breast events than women on tamoxifen (HR 1.76; 95% CI, 1.00-3.12) or women with ER/PgR&lt;50% DIN (HR 1.72; 95% CI, 1.14-2.58). Among untreated patients with ER&gt;50% DIN, recurrence was higher in PgR ≥50% DIN than in PgR &lt;50% DIN, whereas it was similar among low PgR (&lt;50%) DIN against which tamoxifen had no effect. No difference in endometrial cancer incidence was noted.Discussion: High ER and especially high PgR expression is a significant adverse prognostic indicator of DIN against which low-dose tamoxifen appears to be a safe and active treatment. Conversely, women with low expression ER or PgR DIN do not seem to benefit from tamoxifen. A definitive clinical trial is warranted.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 2113.

Randomized phase II trial of budesonide versus placebo in high-risk population with screening-detected lung nodules: Update on secondary endpoints

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Background: Lung cancer phase II chemoprevention trials have not focused so far on the peripheral lung. CT discovers small, undetermined peripheral nodules, which may be preinvasive lesions. In a recent phase II trial the glucocorticoid Budesonide reduced peripheral nodules at spiral CT. Methods: We performed a randomized, double-blind, placebo-controlled, phase IIb clinical trial of inhaled budesonide in current (CS) or former smokers (FS) with CT-detected peripheral nodules. Primary endpoint: shrinkage effect on nodules. Secondary endpoints: decrease in size/number of the target lesions, modulation of tumor markers in sputum and plasma, toxicity, effect on pulmonary function. Two hundred and two subjects received 800μg budesonide (B) twice daily or placebo (P) for 1 year. CT scans at 0 and 12 months (mts), and clinical evaluation + serum/plasma collection at 0, 3, 6, and 12 months were performed. Subjects were stratified according to gender, smoking habits (CS vs. FS), and nodule characteristics (solid vs. non-solid). Results: Preliminary data had shown no shrinkage of the nodules in the B treated arm in a per subject analysis (primary objective). We present now results on serum markers (ultrasensitive C-reactive protein, CRP), emphysema and pulmonary function. As compared to baseline, CRP median levels show at 12 months a nonsignificant (p = 0.85) reduction: -0.25 ± 0.63 (B) vs. -1.16 ± 0.97 (P). 12-month values are significantly (p = 0.01) associated with baseline values and smoking status, with higher mean values at 12 months in FS (B 2.1 ± 2.0 vs. P 3.4 ± 1.9). Emphysema values at 12 months are significantly higher (p = 0.0022) in the B (+ 0.29 ± 0.06) versus P arm (+ 0.12 ± 0.07). This difference is not correlated to sex (p = 0.7062) and smoking status (p = 0.8044). As regards spirometry, no significant difference on FEV 1% and DLC/VA appears between arms at 12 months: median FEV 1% values 3.7 ± 1.0 for B versus 2.9 ± 1.0 for P (p = 0.6221); median DLC/VA increase of 0.3 ± 1.9 (B) versus decrease of -3.8 ± 1.6 (P) (p = 0.4191). Conclusions: A significant effect of B on ultrasensitive-CRP and pulmonary function has not been shown. CRP results may indicate the lack of systemic absorption of B. Emphysema appears slightly worse in the B arm, particularly in FS; this is worth further investigation.

No significant financial relationships to disclose.

Quality of Life endpoints in prostate chemoprevention trials

Although the ultimate goal of any chemoprevention study is to extend life by preventing cancer, it is also important that in doing so, the quality of life is not reduced. Hence, quality of life (QOL) endpoints are secondary only in importance to survival as an endpoint for prostate chemoprevention trials. One can conceptualize QOL endpoints as just another surrogate endpoint biomarker. QOL can be administered and collected in a valid and reliable fashion from cancer patients as demonstrated by numerous clinical trials. To date more than 25 prostate cancer QOL tools have been developed with over 700 different items. However, patients may be asymptomatic, leaving the sensitivity and specificity of the QOL instrumentation in question. Judicious use of a global QOL measure supplemented by protocol-specific or disease-specific instruments is an efficient approach for prostate chemoprevention trials. Clinical significance and missing data considerations need to be elucidated a priori in definitive terms so that results are directly interpretable from the data obtained. The effect of chemopreventive agents on QOL needs to be sufficiently modest to be practical to justify administration in a healthy population. As such, great care needs to be given to a priori determination of the QOL constructs that are most likely to change.

Recommendations for follow-up care of individuals with an inherited predisposition to cancer. II. BRCA1 and BRCA2. Cancer Genetics Studies Consortium

OBJECTIVE

To provide recommendations for cancer surveillance and risk reduction for individuals carrying mutations in the BRCA1 or BRCA2 genes.

PARTICIPANTS

A task force with expertise in medical genetics, oncology, primary care, gastroenterology, and epidemiology convened by the Cancer Genetics Studies Consortium (CGSC), organized by National Human Genome Research Institute (previously the National Center for Human Genome Research).

EVIDENCE

Studies evaluating cancer risk, surveillance, and risk reduction in individuals genetically susceptible to breast and ovarian cancer were identified using MEDLINE (National Library of Medicine) and from bibliographies of articles thus identified. Indexing terms used were "genetics" in combination with "breast cancer," "ovarian cancer," and "screening," or "surveillance" in combination with "cancer family" and "BRCA1" and "BRCA2." For studies evaluating specific interventions, quality of evidence was assessed using criteria of the US Preventive Services Task Force.

CONSENSUS PROCESS

The task force developed recommendations through discussions over a 14-month period.

CONCLUSIONS

Efficacy of cancer surveillance or other measures to reduce risk in individuals who carry cancer-predisposing mutations is unknown. Based on expert opinion concerning presumptive benefit, early breast cancer and ovarian cancer screening are recommended for individuals with BRCA1 mutations and early breast cancer screening for those with BRCA2 mutations. No recommendation is made for or against prophylactic surgery (eg, mastectomy, oophorectomy); these surgeries are an option for mutation carriers, but evidence of benefit is lacking, and case reports have documented the occurrence of cancer following prophylactic surgery. It is recommended that individuals considering genetic testing be counseled regarding the unknown efficacy of measures to reduce risk and that care for individuals with cancer-predisposing mutations be provided whenever possible within the context of research protocols designed to evaluate clinical outcomes.

Recommendations for follow-up care of individuals with an inherited predisposition to cancer. I. Hereditary nonpolyposis colon cancer. Cancer Genetics Studies Consortium

OBJECTIVE

To provide recommendations for cancer surveillance and risk reduction for individuals carrying mutations associated with hereditary nonpolyposis colon cancer (HNPCC).

PARTICIPANTS

A task force with expertise in medical genetics, oncology, primary care, gastroenterology, and epidemiology convened by the Cancer Genetics Studies Consortium (CGSC), organized by the National Human Genome Research Institute (previously the National Center for Human Genome Research).

EVIDENCE

Studies evaluating cancer risk, surveillance, and risk reduction in individuals genetically susceptible to colon cancer were identified using MEDLINE and bibliographies of articles thus identified. Indexing terms used were "genetics" in combination with "colon cancer," and "screening" in combination with "cancer family" and "HNPCC." For studies evaluating specific interventions, quality of evidence was assessed using criteria of the US Preventive Services Task Force.

CONSENSUS PROCESS

The task force developed recommendations through discussions over a 14-month period.

CONCLUSIONS

Efficacy of cancer surveillance or other measures to reduce risk in individuals who carry cancer-predisposing mutations is unknown. Based on observational studies, colonoscopy every 1 to 3 years starting at age 25 years is recommended for individuals known to have HNPCC-associated mutations. Endometrial cancer screening is also recommended, based on expert opinion concerning presumptive benefit. No recommendation is made for or against prophylactic surgery (ie, colectomy, hysterectomy); these surgeries are an option for mutation carriers, but evidence of benefit is lacking. It is recommended that individuals considering genetic testing be counseled regarding the unknown efficacy of measures to reduce risk and that care for individuals with cancer-predisposing mutations be provided whenever possible within the context of research protocols designed to evaluate clinical outcomes.

Clinical management of superior vena cava syndrome

SVCS is a relative medical emergency because it is usually the result of partial or complete occlusion of the SVC by a malignant tumor. Obstruction of the SVC is mimicked by few other organic problems. The traditional view of therapy protocols is that treatment can and should be started before an etiologic diagnosis is made. More recent literature holds that difficulties arise when treatment is started before a cause and location are known. The therapy of choice for this localized problem is radiation therapy. High-dose, short-interval radiation is the primary treatment around which diuretics, steroids, and anticoagulants are added as adjuvants. Most patients treated with radiation therapy respond subjectively within 72 hours and show objective signs of relief within 7 days. The overall survival rate is dependent on the underlying malignancy. Nursing care focuses on the early detection of symptoms of SVCS and the emergency nature of the acute phase. Side effects of therapy and nursing care needs result from therapy as well as from the underlying disease. The psychosocial stressors on the patient and the family are an integral part of the nursing care. The goals of nursing management are good supportive care, astute assessment, and monitoring of the patient's condition. Finally, SVCS is a relative medical emergency. This entity has been described for many years, but it is often misunderstood and mismanaged. The goal of medical management is a rapid diagnostic work-up and the administration of palliative radiation therapy to alleviate the symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)