Abstract P6-02-11: The TILs-US scores based on ultrasonography can predict lymphocyte-predominant breast cancer before surgery

[Purpose]

Tumor-infiltrating lymphocytes (TILs) has been shown to be useful for predicting outcomes after surgery in breast cancer, and while TILs can be evaluated in preoperative biopsy tissue, heterogeneous distribution of TILs requires examination of all biopsied tissue samples.

We gave scores to preoperative ultrasonography (US) images with characteristics indicative of lymphocyte-predominant breast cancer (LPBC) and attempted to apply these for diagnostic prediction of LPBC. In this study, TILs-US scores based on preoperative US were assessed for their usefulness in predicting LPBC, the diagnosis of which was confirmed with postoperative pathology.

[Methods]

We evaluated 161 patients with invasive breast cancer between January 2014 and December 2017. All patients were treated by either mastectomy or breast-conserving surgery. Stromal lymphocytes were evaluated on preoperative biopsy tissues and surgical pathological specimens. Breast cancer samples with ≥ 50% stromal TILs were defined as pre-LPBC (preoperative biopsy tissues) and LPBC (surgical pathological specimens). TILs-US score was calculated from US before curative surgery. Based on clinicopathological factors including TILs-US scores based on preoperative US and pre-LPBC indicators, determinants useful for prediction of LPBC were examined.

[Results]

There were 39 cases of LPBCs and 122 cases of non-LPBCs in surgical pathological specimens. We set TILs-US score cut-offs for predicting LPBC at 4 points based on the receiver operating characteristics (ROC) curves (AUC, 0.88). There were significant predictors for LPBC in maltivariate logistic analysis (TILs-US score: OR26.8, p<0.001; pre- LPBC: 18.6, p=0.002; HER-2: OR9.2, p=0.009) in preoperative clinicopathological factor. The sensitivity, specificity and accuracy of TILs-US score for predicting LPBC were 0.74 (0.62-0.84), 0.89 (0.85-0.92) and 0.85 (0.79-0.90). Those of pre-LPBC were 0.51(0.42-0.55), 0.98 (0.96-1.00) and 0.87 (0.82-0.89), and those of HER2 were 0.28(0.19-0.36), 0.94(0.91-0.97) and 0.78 (0.74-0.82), respectively. The sensitivity of TILs-US score for predicting LPBC was significantly greater than those of pre- LPBC (p=0.04) and HER2 (p<0.001). On the other hand, the specificity of pre- LPBC for predicting LPBC was significantly greater than that of TILs-US score(p=0.002).

The sensitivity, specificity and accuracy of predicting LPBCPerformance measureTILs-US score (95%CI)Preoperative biopsyHER-2P, TILs-US score vs. Preoperative biopsyP, TILs-USscore vs. HER-2Sensitivity0.74 (0.62-0.84)0.51 (0.42-0.55)0.28 (0.19-0.36)0.04<0.001Specificity0.89 (0.85-0.92)0.98 (0.96-1.00)0.94 (0.91-0.97)0.0020.11Accuracy0.85 (0.79-0.90)0.87 (0.82-0.89)0.78 (0.74-0.82)0.230.11

[Conclusions]

TILs-US scores are an important factor that can predict LPBC preoperatively. The TILs-US score has particularly high sensitivity and may be an applicable index in the preoperative evaluation for LPBC.

Citation Format: Kanou A, Masumoto N, Shiroma N, Fukui K, Sasada S, Emi A, Kadoya T, Yokozaki M, Arihiro K, Okada M. The TILs-US scores based on ultrasonography can predict lymphocyte-predominant breast cancer before surgery [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-11.

Abstract P6-02-06: Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction

[Purpose]

Tumor-infiltrating lymphocytes (TILs) is a prognostic factor for breast cancer, however, an accurate and simple evaluation method remains elusive. Therefore, we focused on findings characteristic of lymphocyte-predominant breast cancer (LPBC) in ultrasound (US) images. In this study, the application of preoperative US image assessment to diagnostic prediction of LPBC evaluated from postoperative pathological specimens, was appraised.

[Methods]

We evaluated 191 patients with invasive breast cancer between January 2014 and December 2017. All patients were treated by either mastectomy or breast-conserving surgery. Stromal lymphocytes were evaluated on surgical pathological specimens. Breast cancer samples with ≥ 50% stromal TILs were defined as LPBC. Preoperative US was performed in all cases and images were examined for characteristics indicative of TILs. Scores were given to US images with characteristic TILs and these TILs-US scores were assessed for their application to predict LPBC.

[Results]

There were 39 cases of LPBCs and 122 cases of non-LPBCs in surgical pathological specimens.

The characteristic US image findings predicting LPBC were shape (more lobulated), internal echo level (weaker) and posterior echoes (stronger). The TILs-US scores were given based on these three ultrasound tissue characterizations.We set TILs-US score cut-offs for predicting LPBC at 4 points (Sensitivity, 0.73; specificity, 0.87; accuracy, 0.83) based on the receiver operating characteristics (ROC) curves (AUC, 0.88). There were significant predictors for LPBC in maltivariate logistic analysis (Nuclear Grade (NG): OR3.4, p=0.02; ER: 5.7, p =0.007;HER-2: OR4.1, p=0.04; TILs-US score2: OR14.9, p<0.001) in preoperative clinicopathological factor. The sensitivity, specificity and accuracy of NG for predicting LPBC were 0.75, 0.69 and 0.71. Those of ER and HER2 were 0.33, 0.96 and 0.79.Sensitivity, specificity, and accuracy of NG, ER, and HER2 diagnoses were all lower than the TILs-US score, and the TILs-US score showed the best diagnostic ability.

The sensitivity, specificity and accuracy of predicting LPBCPerformance measureTILs-US score (95%CI)NGER or HER-2P, TILs-US score vs. NG,P, TILs-USscore vs. ER or HER-2Sensitivity0.73 (0.63-0.81)0.75 (0.64-0.84)0.327 (0.24-0.39)0.08<0.001specificity0.87 (0.83-0.90)0.69 (0.65-0.72)0.957 (0.93-0.98)<0.001<0.001accuracy0.83 (0.77-0.88)0.707 (0.65-0.376)0.785 (0.74-0.82)0.0040.25

Conclusions

LPBC has characteristic ultrasound tissue characterizations in US images. Thus, TILs-US scores based on US may be applicable to accurate and convenient preoperative diagnosis of LPBC.

Citation Format: Fukui K, Masumoto N, Shiroma N, Kanou A, Yokozaki M, Sasada S, Emi A, Kadoya T, Arihiro K, Okada M. Characteristics of lymphocyte-predominant breast cancer in ultrasound images and their application to diagnostic prediction [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-06.

Abstract P6-02-09: Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy

Background: Neoadjuvant chemotherapy (NAC) is a standard treatment for operable breast cancer. However, imaging methods for evaluating treatment response have not been established. Previous studies reported that ring-type dedicated breast positron emission tomography (DbPET) detected residual tumors following NAC more accurately than whole-body PET/CT. This study assessed DbPET parameters for predicting pathological complete response (pCR) in patients with breast cancer.

Patients and Methods: Among patients with breast cancer who underwent surgery after NAC, 61 were examined using ring-type DbPET before and after NAC. The maximum standardized uptake values (SUVmax) and tumor-to-normal-tissue ratio (TNR) were calculated before and after NAC (pre-SUVmax, pre-TNR, post-SUVmax and post-TNR, respectively). Moreover, the reduction rates (ΔSUVmax and ΔTNR) were determined. pCR was defined as complete remission of breast cancer.

Results: The median patient age was 52 years. Forty patients (65.6%) were estrogen receptor (ER)-positive, whereas 25 patients (41.0%) were HER2-positive. Fifteen patients (24.6%) achieved pCR after NAC. The calculated values for the parameters of DbPET are summarized in Table 1. The most promising parameters for predicting pCR were ΔSUVmax (area under the curve [AUC]: 0.506) and post-TNR (AUC: 0.640). Although neither of these two parameters reflected the pathological response to NAC in patients with ER-positive disease, post-TNR showed the highest AUC (i.e., AUC: 0.750) for pCR in patients with ER-negative disease. The sensitivity and specificity of post-TNR in the ER-positive group were 85.7% and 39.4%, respectively. In the ER-negative group, these values were 100% and 58.3%, respectively [Table 2]

Table 1.Diagnostic performance of dedicated breast positron-emission tomography for the prediction of pathological complete response after neoadjuvant chemotherapyParameterspCR Median (IQR)Non-pCR Median (IQR)PAUC (95% CI)Pre-SUVmax14.8 (9.2–17.7)14.4 (10.7–19.8)0.6040.454 (0.285–0.624)Post-SUVmax1.8(1.5–2.1)2.0 (1.6–3.4)0.2370.603 (0.460–0.746)ΔSUVmax (%)87.32 (81.5–91.8)88.6(82.8–91.8)0.9540.506 (0.329–0.682)Pre-TNR8.0 (5.3–9.2)7.3(5.9–10.2)0.7570.472 (0.297–0.647)Post-TNR1.7(1.0–1.1)1.2 (1.0–2.4)0.0980.640 (0.506–0.774)ΔTNR (%)87.3 (78.3–89.1)79.8 (62.7–86.7)0.1130.638 (0.472–0.803)pCR, pathological complete response; IQR, interquartile range; AUC, area under the curve; CI, confidence interval, SUV, standardized uptake value; TNR, tumor-to-normal-tissue ratio.Table 2.Diagnostic accuracy of post-TNR according to estrogen receptor status Sensitivity (%)Specificity (%)Accuracy (%)PPV (%)NPV (%)ER-positive85.739.447.523.192.9ER-negative10058.375.061.5100TNR, tumor-to-normal-tissue ratio; ER, estrogen receptor; PPV, positive predictive value; NPV, negative predictive value

Conclusion: In DbPET, ΔSUVmax and post-TNR were shown to be promising parameters for predicting pathological response to NAC. Post-TNR provided the highest sensitivity for predicting pCR in patients with ER-negative breast cancer.

Citation Format: Suzuki E, Sasada S, Sueoka S, Masumoto N, Goda N, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Diagnostic performance of dedicated breast PET for the prediction of pathological response after neoadjuvant chemotherapy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-09.

Abstract P6-02-17: Hand-held impulse-radar detector for breast cancer: development and a pilot study

Background: Microwave breast imaging, which using the difference in the dielectric properties between breast cancer and normal breast tissue, is a painless and non-radiation method. We have created a novel hand-held prototype of breast cancer detector using impulse-radar based imaging system, and conducted a pilot clinical study.

Methods: The detector consists of complementary metal-oxide-semiconductor (CMOS) integrated circuits covering the ultrawideband width from 3.1 to 10.6 GHz, which enable the generation and transmission of Gaussian monocycle pulse (GMP) trains and single port eight throw switching matrices (SP8T-SW) for controlling a 4×4 cross-shaped dome antenna array. The size of the detector was 19.1 × 17.7 × 18.8 cm. After evaluation using a breast tumor phantom and the resected breast specimens obtained through mastectomy, we recruited 5 patients with histologically confirmed breast cancers in the clinical study. The detector was placed on the breast with the patient in a supine position. The primary endpoint was a detection rate of breast cancers, and the secondary endpoints were positional accuracy and adverse event. This study was registered with the UMIN Clinical Trials Registry (UMIN000026181).

Results: The three-dimensional positions of the tumors in the imaging results using a phantom and resected specimens are consistent with the results of histopathology analysis. In the clinical study, all 5 targeted breast cancers were detected and were visualized at the sites confirmed by other diagnostic modalities. Among 5 tumors, one was not detected via mammography because of heterogeneously dense breast and another was a microinvasive carcinoma of invasive tumor size 0.5 mm. No study-related adverse events occurred.

Conclusions: We succeeded in creating a new device of hand-held impulse-radar detector for breast cancer. The detector has sufficient detective capability, is safe for clinical use, and might detect an early stage breast cancer. In the future, we will proceed with the development to clinical application.

Citation Format: Sasada S, Masumoto N, Song H, Goda N, Kajitani K, Emi A, Kadoya T, Arihiro K, Kikkawa T, Okada M. Hand-held impulse-radar detector for breast cancer: development and a pilot study [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P6-02-17.

Abstract P5-02-03: Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography

Background: Dedicated breast positron emission tomography (DbPET)provides detailed high resolution images of the breast and enables quantitative assessment using standard uptake values (SUVs). We aimed to determine whether DbPET can predict the pathological malignancy grade and neoplastic progress of breast cancer compared with whole body (WB) PET.

Methods: We investigated 196 consecutive patients with invasive breast cancerwho underwent concurrent Db- and WB-PET from January 2016 to March 2017. All Db- and WB-PET were quantified based on SUVs. We also investigated pathological features of breast cancer who had a ring-like uptake (RU) without central FDG accumulation on DbPET.

Results:

The associations between the SUVs for DB- and WB-PET and the pathological factors in breast cancerCharacteristicSUV WBPETDbPET Mean ± SDpMean ± SDpall3.6 ± 3.4 9.4±7.9 Tumor size    ≤2.0 cm2.2±1.6<0.0016.5±5.2<0.001>2.0 cm5.5±4.1 13.3±9.2 LN    Negative3.1±3.3<0.0018.4±7.8<0.001Positive4.9±3.2 11.8±7.7 NG    1 or 22.4±2.1<0.0016.6±5.9<0.00135.1±4.0 12.7±8.7 Ki67    < 201.8±1.1<0.0015.2±3.3<0.001≥ 204.4±3.7 11.4±8.6 ER    positive3.4±3.30.028.8±7.60.006negative5.2±3.6 13.5±8.6 HER-2    positive4.6±3.10.0911.8±7.60.04negative3.4±3.4 9.0±7.9 Sub type vs Lumnal A vs Lumnal ALuminal A1.8±1.1 5.2±3.3 Luminal B4.0±3.8<0.00110.1±8.5<0.001HER24.6±3.1<0.00111.8±7.6<0.001Triple negative5.3±3.8<0.00113.8±9.2<0.001

summarizes the association between SUVs for Db- and WB-PET and pathological factors inbreast cancer.SUVs on PET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm (p<0.001), for LN-positive than for LN-negative (p<0.001), for NG3 than for NG1-NG2 (p<0.001), for higher Ki67 expression than for lower Ki67 expression (p<0.001), and for ER-negative than for ER-positive (WBPET, p=0.02; DbPET, p=0.006). SUVs were significantly lower for Luminal A than for Luminal B, HER2, and triple-negative cancer (p<0.001 for all three).SUVs for DbPET was significantly higher for HER2-positive than for HER2-negative (p=0.02).

The association between SUVs for breast cancer with and without RU on DbPETCharacteristicRU(-), nRU(+), npall17323 Tumor size   ≤2.0 cm1095<0.001>2.0 cm6418 LN   Negative1299<0.001Positive4414 NG   1 or 210070.0237316 Ki67   < 206130.03≥ 2011220 ER   positive152190.49negative214 HER-2   positive2620.38negative14721 Sub type  vs Lumnal ALuminal A493 Luminal B84150.02HER22620.81Triple negative1430.04

summarizes the association between SUVs for breast cancer with and without RU on DbPET. SUVs for breast cancer with RU on DbPET were significantly higher for the tumor size of >2.0 cm than for tumor size ≤2.0 cm, for LN -positive than for LN-negative (p<0.001), for NG3 than for NG1-2 (p=0.02), and for higher Ki67 expression than for lowerKi67 expression (p=0.03). SUVs were significantly lower for Luminal A than for Luminal B (p=0.02) and triple-negative cancer (p=0.04).

Conclusions: SUVs for DbPET were equal or superiorto WBPET in predicting the pathological malignancy grade and neoplastic progress in tumors. Furthermore, the presence of RU on DbPET can provide excellent predictive value for high-grade malignancy and might help to determine appropriate therapeutic strategies.

Citation Format: Masumoto N, Kadoya T, Nishina M, Kimura Y, Suzuki E, Sueoka S, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kataoka T, Okada M. Evaluation of pathological malignancy grade and neoplastic progress of breast cancer using dedicated breast positron emission tomography [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 P5-02-03.

Abstract P6-03-08: Detection ability of dedicated breast positron emission tomography for small-sized breast cancer

Background: Whole body (WB) 18F-fluorodeoxyglucose positron emission tomography (PET) has a relatively poor spatial resolution (>1 cm), which limits the capability to detect small lesions. Therefore, small-sized breast cancers (≤1 cm) may not be visible on WBPET. To overcome these limitations, dedicated breast PET (DbPET) has been developed to improve spatial resolution. DbPET enables detailed high-resolution images within the breast. We aimed to determine whether DbPET can detect small-sized breast cancer compared to WBPET.

Methods: We investigated 203 consecutive patients (217 tumors) (T1–3, N0–3a, M0) with breast cancer who underwent concurrent DbPET and WBPET between January 2016 and March 2017. All DbPET and WBPET images were semi-quantified based on standard uptake values. The diagnostic performance of each scanner was assessed in DbPET and WBPET. Tumors were classified based on pathological classification as follows: Tis, ductal carcinoma in situ (DCIS); T1a, ≤0.5 cm; T1b, 0.5–1 cm; and T1c, 1–2 cm; T2, 2–5 cm; T3, >5 cm. The sensitivities of DbPET and WBPET were compared in each size group.

Results: Table 1 shows the detection rate of breast cancer in WBPET and DbPET

The detection rate of breast cancer in WB- and Db-PET DbPETWBPETpTumor sizeDetection (-) n(%)Detection (+) n(%)Detection (-) n(%)Detection (+) n(%) Tis6(14.6)35(85.4)18(43.9)23(56.1)0.0030T1a2(8)23(92)7(28)18(72)0.0594T1b2(6.5)29(93.5)10(32.3)21(67.7)0.0077T1c5(8.2)56(91.8)11(18)50(82)0.1038T20(0)57(100)1(1.8)56(98.2)0.2375T30(0)2(100)0(0)2(100)-total15(6.9)202(93.1)47(21.7)170(78.3)<0.0001

. The overall detection rate in DBPET [93.1% (202/217)] was significantly higher than that of WBPET [78.3% (170/217)] (P < 0.001). For smaller tumors, DbPET was more sensitive than WBPET: Tis (85.4% vs. 56.1%), T1a (92% vs. 72%), T1b (93.5% vs. 67.7%), T1c (91.8% vs. 82%), T2 (100% vs. 98.2%), and T3 (100% vs. 100%). The sensitivity of DbPET was significantly higher than that of WBPET in Tis (P = 0.003) and T1b (P = 0.008) and tended to be higher than that of WBPET in T1a (P = 0.059). Conversely, no significant differences were observed in T1c (P = 0.103) and T2 (P = 0.238).

Conclusion: The imaging sensitivity of DbPET was higher than that of WBPET. DbPET showed significant sensitivity in DCIS and tumors ≤1 cm, which is a weak point for WBPET. DbPET may serve as a new diagnostic modality to detect small-sized breast cancer.

Citation Format: Sueoka S, Masumoto N, Nishina M, Kimura Y, Suzuki E, Goda N, Sasada S, Kajitani K, Emi A, Haruta R, Kadoya T, Kataoka T, Okada M. Detection ability of dedicated breast positron emission tomography for small-sized breast cancer [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 P6-03-08.

Abstract P4-02-06: Evaluation of contrast-enhanced ultrasonography for early prediction of response to neoadjuvant chemotherapy in triple negative breast cancer

Objectives

We aimed to determine whether contrast-enhanced ultrasonography (CEUS) can predict the early effects of neoadjuvant chemotherapy on triple negative breast cancer.

Methods

The clinical responses of 20 consecutive patients with breast cancer (T1–2, N0–1, M0) to neoadjuvant chemotherapy between October 2012 and Feb 2016 were assessed using ultrasonography and contrast-enhanced ultrasonography before starting the therapy and after the treatment of 2 courses. Ascending slope (AS) of perfusion parameters for contrast-enhanced ultrasonography were created from time–intensity curves based on enhancement intensity and temporal changes to objectively evaluate contrast-enhanced ultrasonography findings.We investigated whether rate of change of ascending slope (ΔAS) and tumor size (Δ US) could predict pCR.

Results

Eight (40.0%) of the 20 patients achieved pathological complete response. ΔAS were significantly higher (-25.5 ± 35.5 vs. 14.7 ± 33.2; P < 0.02) in patients who achieved pCR than in those who did not. On the other hand, ΔUS of pCR and non-pCR did not significantly differ among tumors (-40.8 ± 22.4 vs. -21.4 ± 20.6; P = 0.06). The AUC values for ΔAS and ΔUS were 0.792 (95% CI, 0.579 -1.000, P = 0.03) and 0.729 (95% CI, 0.501 - 0.957;p = 0.09), respectively. We set ΔAS and Δ US cut-offs for predicting pCR at-20.08 and - 33.75 based on the ROC curves. Clinical and pathological characteristics of the 20 patients are summarized in Univariate (odds ratio, 2.71; p= 0.02) and multivariate (odds ratio, 2.88; p= 0.03) analysis showed that ΔAS was the sole independent predictor of pCR.

Clinical and pathological characteristics of patients with breast cancer.CharacteristicpCR (n)Non pCR (n)pClinical T status   T1110.71T2711 Clinical N status   Negative570.85Positive35 Nuclear Grade   1 or 2340.85358 ΔUS (%)   < -33.75390.09≥ -33.7553 ΔAS (%)   < -20.082100.009≥ -20.0862 

Univariate and multivariate logistic analysis of significant predictive factors for pCR in triple negative subtype Univariate analysisMultivariate analysis OR, 95% CI, pOR, 95% CI, pΔUS  > -33.751.61, 0.72-34.7, 0.101.85, 0.51-79.1, 0.15≤-33.75  ΔAS  > -20.082.71, 1.65-136.1, 0.022.88, 1.44-218.7, 0.03≤ -20.08  

Conclusion

ΔAS assessed with CEUS can help the physician to early predict the probability of achieving pCR or not.

Citation Format: Masumoto N, Kadoya T, Murakami C, Gouda N, Sasada S, Emi A, Haruta R, Kataoka T, Okada M. Evaluation of contrast-enhanced ultrasonography for early prediction of response to neoadjuvant chemotherapy in triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-02-06.

Abstract P1-15-03: Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial

Background

Prevention of letrozole–induced bone loss using oral risedronate has not been proved in the Japanese women. The aim of this study was to assess the effect of risedronate 17.5mg/week on bone mineral density (BMD) in postmenopausal, early breast cancer patients scheduled to receive adjuvant letrozole.

Patients and Methods

Postmenopausal women with hormone receptor–positive early breast cancer were assigned to one of two strata according to their baseline BMD T-score as being at low and high risk of osteoporosis. Patients with low risk (-2.5 ≤ T score) were randomly assigned to letrozole and risedronate (L+R) or to letrozole alone (L). Patients with high risk (-2.5 > T score) received letrozole and risedronate (L+R). Letrozole was given at a dosage of 2.5 mg/day while oral risedronate was given at 17.5mg/week. The primary end point was the change in lumbar spine (LS) BMD at 12 months. The secondary end points included change in total hip (HP) BMD and bone turnover markers.

Results

In the low risk group (N=103), treatment with L+R resulted in a significant increase in BMD at LS and at HP compared to treatment with L only at 12 months (1.8% vs -2.2%, P < 0.001, and -0.3% vs -2.9%, P = 0.001, respectively). In the L+R group, significant decreases in bone turnover makers, NTX and PINP, were recognized compared with L only at 12months (-11.1% vs. 27.5%, P<0.001, -42.3% vs. 15.2%, P<0.001, respectively). In the high risk group (N=28), treatment with L+R resulted in a significant increase in BMD at LS and prevention of decrease in BMD at HP (3.6%; 95%CI, 1.8% to 5.3%, p=0.003, 0.3%; 95%CI, -1.3% to 1.8%, p=0.47, respectively).

Estimated Percentage Change From Baseline to 6 and 12 Months in Lumbar Spine and Total Hip BMD   From Baseline to 6 MonthsFrom Baseline to 12 MonthsBMD areaRisk GroupTreatmentChange in BMD (%), 95% CIPChange in BMD (%), 95% CIPLumbar spineLow riskL+R1.7 (-1.3 to 4.7)<0.0011.8 (-2.1 to 5.7)<0.001  L-1.6 (-4.3 to 1.1) -2.2 (-5.7 to 1.3)  High riskL+R1.8 (0.4 to 3.2)0.043.6 (1.8 to 5.3)0.003Total hipLow riskL+R-0.2 (-2.7 to 2.3)0.001-0.3 (-3.2 to 2.6)0.001  L-2.2 (-5.4 to 1.0) -2.9 (-7.2 to 1.4)  High riskL+R0.1 (-1.3 to 1.6)0.610.3 (-1.3 to 1.8)0.47BMD: bone mineral density, L: Letrozole, R: risedronate

Four patients (14.3%) improved from osteoporotic region to the osteopenic region with L+R treatment. Letrozole and risedronate were well tolerable and there was no serious adeverse event including osteonecrosis of jaw.

Conclusions

At 12 months, 17.5mg/week risedronate therapy prevented bone loss in postmenopausal women with breast cancer who were receiving adjuvant letrozole, of which results were compatible with previous findings of western populations.

Citation Format: Kadoya T, Masumoto N, Shigematsu H, Emi A, Kajitani K, Kobayashi Y, Funakoshi M, Kawabuchi Y, Ohara M, Matsuura K, Noma M, Sasada T, Okada M. Prevention of letrozole–induced bone loss using risedronate in postmenopausal women with hormone receptor positive breast cancer: A multicenter randomized clinical trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P1-15-03.

Abstract P4-09-17: Wnt5a expression is associated with high-grade malignancy in ER-positive breast cancer

Background: Wnt5a is a representative ligand that activates the β-catenin-independent pathways. The purpose of our study is to elucidate the implication of Wnt5a expression in breast cancer.

Materials and methods: One hundred seventy eight breast cancer patients (mean age ± SD: 59.6 ± 13.2 years) with clinical Stage I∼III between January 2011 and February 2014, were prospectively evaluated. Patients who underwent operation without neoadjuvant therapy were enrolled to this study. The immunohistochemical analyses of Wnt5a protein was performed to evaluate relationships between Wnt5a expression and clinicopathological factors. MCF7 cells that stably express Wnt5a were generated and used for cDNA microarray analyses to investigate Wnt5a-dependent gene expression.

Results: Wnt5a expression was significantly more frequent when estrogen receptor (ER) was present, 68/153 (44%) than when ER was absent, 1/25 (4%) (p<0.001). Wnt5a expression was also related with progesterone receptor (PgR) (P<0.001), but not with HER2 status (P=0.496). In ER-positive breast cancer, a significant interaction between expression of Wnt5a with lymph node metastasis (P<0.001), nuclear grade (P=0.004), lymphatic invasion (P=0.002), vessel invasion (P=0.050), and pStage (P<0.001). Microarray analyses identified several genes induced by Wnt5a (>3.0 fold), involving activated leukocyte cell adhesion molecule (ALCAM). ALCAM is known to be related with apoptosis, invasion and prognosis of breast cancer. Wnt5a expression levels correlated with those of ALCAM in ER-positive tumor samples from patients by immunohistochemical analyses (P<0.001).

Relationship between Wnt5a expression and clinicopathological featureClinicopathological featuretotalWnt5a expressionP value (n=153)Negative (n=85)Positive (n=68) Age (median, range) 63, 35-8657.5, 34-870.065Age, n (%)    ≤4528 (18)13 (46)15 (54) >45125 (82)72 (58)53 (42)0.282Menopausal status, n (%)    Premenopausal58 (38)27 (47)31 (53) Postmenopausal95 (62)58 (61)37 (39)0.080Tumor size, n (%)    pT1 ≤20mm104 (44)63 (61)41 (39) pT2/pT3 >20mm49 (56)22 (45)27 (55)0.069lymph node metastasis, n (%)    Negative103 (67)72 (70)31 (30) Positive50 (33)13 (26)37 (74)<0.001Nuclear grade, n (%)    1/285 (56)56 (66)29 (34) 368 (44)29 (43)39 (57)0.004Lymphatic invasion, n (%)    Negative101 (66)65 (64)36 (36) Positive52 (34)20 (38)32 (62)0.002Vessel invasion, n (%)    Negative142 (93)82 (58)60 (42) Positive11 (7)3 (27)8 (73)0.050Ki-67, n (%)    0-2067 (44)43 (64)24 (36) 21-10086 (56)42 (49)44 (51)0.058pStage, n (%)    pStage I80 (52)58 (73)22 (28) pStage II64 (42)27 (42)37 (58) pStage III9 (6)0 (0)9 (100)<0.001ALCAM, n (%)    Negative85 (56)64 (75)21 (25) Positive68 (44)21 (31)47 (69)<0.001

Conclusions: Wnt5a express in ER-positive breast cancer and are associated with high-grade malignancy. Wnt5a could be a prognostic factor of ER-positive breast cancer. These results have implications that Wnt5a may become a preoperative and postoperative assessment tool for tumor malignancy grade and a potential therapeutic target except endocrine therapy in ER-positive breast cancer. In future studies, further research on Wnt5a are required to develop a novel treatment for more improved outcomes in a great variety of breast cancer.

Citation Format: Kobayashi Y, Kadoya T, Gouda N, Kajitani K, Emi A, Shigematsu H, Masumoto N, Okada M. Wnt5a expression is associated with high-grade malignancy in ER-positive breast cancer. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P4-09-17.

Abstract P2-03-07: Prediction of the pathological response to neoadjuvant chemotherapy in patients with breast cancer using sonazoid-enhanced ultrasonography

Background:

Altered blood flow in malignant tumors is evidenced by contrast-enhanced ultrasonography (CEUS) because of its image perfusion capabilities.

This study aimed to investigate the value of CEUS in the evaluation of the response of breast cancer lesions to neoadjuvant chemotherapy (NAC). We evaluated whether the prediction of a pathological complete response (pCR) using CEUS was more precise than that using other standard evaluation methods such as magnetic resonance imaging (MRI) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT).

Methods:

Ten patients (mean age, 50.2 years) who underwent NAC for invasive breast cancer between September 2012 and April 2013 were eligible for this cohort study. Clinical tumor response was evaluated using contrast-enhanced MRI, PET/CT, and CEUS following NAC. A pCR was defined as the absence of invasive cancer in the breast and lymph nodes according to the Japanese Breast Cancer Society criteria.

A clinically complete response (cCR) was defined as the absence of residual disease on MRI and PET/CT. The HI VISION ASCENDUS (Hitachi Aloka Medical Corp.) was used for ultrasonography. Tumors were observed 50 s after Sonazoid injection at a dose of 0.01 ml/kg. A time-intensity curve of tumor signal intensity was drawn. The brightness of the tumor was digitized and the curve was created on the basis of brightness changes over time. The intensity of brightness of the breast cancer lesions was calculated as the increased rate of brightness (IRB) using the following formula: maximal intensity/intensity before contrast.

Results:

Four (40%) of the 10 patients were diagnosed with pCR by NAC. Among 4 (40%) patients diagnosed with cCR by MRI, 1 (25%) achieved pCR. All patients were diagnosed with pCR by PET/CT. The IRB values of the 10 patients who received CEUS before surgery were 1.0, 1.1, 1.2, 1.2, 1.3, 1.6, 1.8, 1.9, 2.5, and 4.2. The IRB values of the 4 patients diagnosed with pCR were 1.0, 1.1, 1.2, and 1.2. IRB values were significantly lower in patients who achieved pCR than in those who did not (pCR vs. no pCR, 1.1 ± 0.9 vs. 2.2 ± 1.0, P < 0.05). Furthermore, among the patients who achieved pCR, the IRB values of 2 patients with no residual ductal carcinoma in situ (DCIS) were 1.0 and 1.1, whereas those of 2 patients with residual DCIS were both 1.2.

In the 4 patients who achieved cCR as diagnosed by MRI and PET/CT, 3 with pathological residual disease had detectable IRB by CEUS.

table 1caseageStageSub typeMRIPET-CTpathological responseIncrease rate of brightness (IRB)167T2N1 IIBLuminal HER2PRCRCR1237T2N0 IIAHER2 positivePRCRCR1.1346T3N1 IIIAHER2 positiveCRCRCR1.2446T2N3c IIICLuminal HER2PRCRCR1.2564T2N0 IIAHER-2 positiveCRCRPR1.3658T2N1 IIBLuminal BCRCRPR1.6738T2N0 IIALuminal BPRCRPR1.8857T1cN0 ILuminal HER-2PRCRPR1.9939T2N1 IIBLuminalBSDCRSD2.51050T2N1 IIBTriple negativePRCRSD4.2

Conclusions:

The prediction of pCR after NAC in patients with breast cancer is more precise with Sonazoid-enhanced ultrasonography than with standard methods such as MRI and PET/CT. Furthermore, CEUS may be useful for predicting residual DCIS on the basis of brightness intensity.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-03-07.

Abstract P4-01-04: Role of FDG-PET/CT in evaluating surgical outcomes of operable breast cancer: Usefulness for malignant grade of triple-negative breast cancer

Background: The aim of this study was to evaluate the significance of 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) for speculating the malignant level and prognostic value of operable breast cancers.

Methods: Of 578 consecutive patients with primary invasive breast cancer who underwent curative surgery between 2005 and 2010, 311 patients (53.8%) who received FDG PET/CT before initial therapy were examined.

Results: Receiver operating characteristics (ROC) curve analysis showed the cutoff value of the maximum standardized uptake value (SUVmax) to predict cancer recurrence was 3.8 in all patients and 8.6 in patients with the triple-negative subtype, respectively. In all patients, 3-year DFS rates were 98.8% for patients with a tumor of SUVmax ≤ 3.8 and 91.6% for patients with a tumor of SUVmax > 3.8 (p < 0.001). High value of SUVmax was significantly associated with large tumor size (p < 0.001), lymph node metastasis (p = 0.040), high nuclear grade (p < 0.001), lymphovascular invasion (p = 0.032), negative hormone receptor status (p < 0.001), and positive HER2 status (p = 0.014). Based on the results of multivariate Cox analysis in all patients, high SUVmax (p = 0.001) and negative hormone receptor status (p = 0.005) were significantly associated with poor prognosis. In patients with triple-negative subtype, 3-year DFS rates were 90.9% for patients with a tumor of SUVmax ≤ 8.6 and 42.9% for patients with a tumor of SUVmax > 8.6 (p = 0.002), and high SUVmax was the only significant independent prognostic factor (p = 0.047).

Conclusion: FDG-PET/CT is useful for predicting malignant behavior and prognosis in patients with operable breast cancer, especially the triple-negative subtype.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P4-01-04.

Abstract P6-07-26: Prognostic significance of the maximal value of the baseline standardized uptake value on fluorine 18 fluorodeoxyglucose positron emission tomography/computed tomography for predicting pathologic malignancy of operable breast cancer with neoadjuvant chemotherapy

PURPOSE: [18F]-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) is potentially useful in predicting pathological complete response (pCR), disease free survival (DFS) and overall survival (OS) of breast cancer patients with neoadjuvant chemotherapy.

MATERIALS AND METHODS: 77 breast cancer patients (mean age ± SD: 52.6 ± 11.2 years) with clinical Stage I∼III between January 2006 and December 2011, were prospectively evaluated (median follow up period:26.5 months). Neoadjuvant chemotherapy of an anthracycline-based regimen and taxane was performed, and patients underwent a whole-body FDG PET/CT before and after chemotherapy. The maximal value of the baseline standardized uptake values (SUVmax) were assessed for predicting pCR, DFS and OS. For the evaluation of relationship between SUVmax values and prognosticators such as hormone receptors, human epidermal growth factor receptor 2 (HER2), nuclear grade, lymph node metastasis and tumor size, statistical analyses were performed using Student t test and log-rank test, and p values of less than 0.05 were considered to indicate statistically significant differences.

RESULTS: Clinical Stage included were I (n = 2, 2.6%), II (n = 62, 80.5%) and III (n = 12, 15.6%). Tumors with estrogen receptor positive were 52 (67.5%) and negative were 24 (31.2%). Therapeutic response by neoadjuvant chemotherapy was obtained in 15 patients (19.5%) with pCR and 60 (77.9%) without pCR. Patients were divided into two groups according to cut-off SUVmax established on the basis of receiver operating characteristic (ROC) analysis (<6.0 vs. ≥6.0, AUC=0.721). When related to the biologic parameters, estrogen receptor (OR:3.75, 95%Cl:1.36–10.35, p = 0.02), but not progesterone receptor (OR:2.31, 95%Cl:0.89–6.00, p = 0.08) nor HER2 status (OR:1.51, 95%Cl:0.47–4.85, p = 0.70) were found strong relation to SUVmax values.

Sensorless control for a sophisticated artificial myocardial contraction by using shape memory alloy fibre

The authors have been developing an artificial myocardium, which is capable of supporting natural contractile function from the outside of the ventricle. The system was originally designed by using sophisticated covalent shape memory alloy fibres, and the surface did not implicate blood compatibility. The purpose of our study on the development of artificial myocardium was to achieve the assistance of myocardial functional reproduction by the integrative small mechanical elements without sensors, so that the effective circulatory support could be accomplished. In this study, the authors fabricated the prototype artificial myocardial assist unit composed of the sophisticated shape memory alloy fibre (Biometal), the diameter of which was 100 microns, and examined the mechanical response by using pulse width modulation (PWM) control method in each unit. Prior to the evaluation of dynamic characteristics, the relationship between strain and electric resistance and also the initial response of each unit were obtained. The component for the PWM control was designed in order to regulate the myocardial contractile function, which consisted of an originally-designed RISC microcomputer with the input of displacement, and its output signal was controlled by pulse wave modulation method. As a result, the optimal PWM parameters were confirmed and the fibrous displacement was successfully regulated under the different heat transfer conditions simulating internal body temperature as well as bias tensile loading. Then it was indicated that this control theory might be applied for more sophisticated ventricular passive or active restraint by the artificial myocardium on physiological demand.

Assessment of synchronization measures for effective ventricular support by using the shape memory alloy fibred artificial myocardium in goats

Thromboembolic and haemorrhagic complications are the primary causes of mortality and morbidity in patients with artificial hearts, which are known to be induced by the interactions between blood flow and artificial material surfaces. The authors have been developing a new mechanical artificial myocardial assist device by using a sophisticated shape memory alloy fibre in order to achieve the mechanical cardiac support from outside of the heart without a direct blood contacting surface. The original material employed as the actuator of artificial myocardial assist devices was 100um fibred-shaped, which was composed of covalent and metallic bonding structure and designed to generate 4-7 % shortening by Joule heating induced by the electric current input. In this study, we focused on the synchronization of the actuator with native cardiac function, and the phase delay parameter was examined in animal experiments using Saanen goats. Total weight of the device including the actuator was around 150g, and the electric power was supplied transcutaneously. The device could be successfully installed into thoracic cavity, which was able to be girdling the left ventricle. The contraction of the device could be controlled by the originally designed microcomputer. The mechanical contraction signal input had been transmitted with the phase delay of 50-200 msec after the R-wave of ECG, and hemodynamic changes were investigated. Cardiac output and systolic left ventricular pressure were elevated with 20% delay of cardiac cycle by 27% and 7%, respectively, although there was smaller difference under the condition of the delay of over 30%. Therefore, it was suggested that the synchronization measures should be examined in order to achieve sophisticated ventricular passive/active support on physiological demand.

Development of an Artificial Myocardium using a Covalent Shape-memory Alloy Fiber and its Cardiovascular Diagnostic Response

The authors have been developing a newly-designed totally-implantable artificial myocardium using a covalent shape-memory alloy fibre (Biometal®, Toki Corporation), which is attached onto the ventricular wall and is also capable of supporting the natural ventricular contraction. This mechanical system consists of a contraction assistive device, which is made of Ti-Ni alloy. And the phenomenon of the martensitic transformation of the alloy was employed to achieve the physiologic motion of the device. The diameter of the alloy wire could be selected from 45 to 250μm. In this study, the basic characteristics of the fiber of 150μm was examined to design the sophisticated mechano-electric myocardium. The stress generated by the fiber was 400gf under the pulsatile driving condition (0.4W, 1Hz). Therefore it was indicated that the effective assistance might be achieved by using the Biometal shape-memory alloy fiber.

Papanicolaou tests and molecular analyses using new fluid-based specimen collection technology in 3000 Japanese women

A fluid-based Papanicolaou test has been established to improve sample collection and preparation. This study was the first large-scale investigation in Japan to examine the feasibility of using fluid-based Papanicolaou specimens to detect human papillomavirus (HPV) using Hybrid Capture II and polymerase chain reaction (PCR). Three thousand patients who visited Keio University Hospital between October 2000 and February 2001 were enrolled in the study. The results of the fluid-based Papanicolaou tests corresponded well with those of conventional Papanicolaou smears (96.8% concordance). The sensitivities of cervical neoplasia detection using the fluid-based Papanicolaou test (73.9%) and Hybrid Capture II (76.3%, P=0.55) were not significantly different. Among the cervical intraepithelial neoplasia 3 and squamous cell carcinoma specimens, HPV 16 and HPV 52 were predominantly detected using the PCR method. Although some DNA samples extracted from the fluid-based specimens were degradaded, PCR and direct sequencing could be performed without difficulty even after 1 year of specimen storage. We conclude that fluid-based Papanicolaou specimens can be applied to investigate HPV infection.

Additional organizational features of the murine γ-glutamyl hydrolase gene

Analysis of independently isolated clones from a mouse liver cDNA library identified a splice variant of gamma-GH mRNA with novel nucleotide sequence at the 5' end. Genomic sequencing now shows that this variant (variant II) incorporates two new alternates (exons Bla and Blb) of exon 1 in the murine gamma-GH gene remotely situated with respect to the rest of the gene. Further analysis of this variant also showed that it incorporates a small segment at the 3' end of exon A1, revealing that the previously described exon 1 consists of two individual exons (Ala and Alb) joined at a cryptic splice site. The 5' UTR and a segment of the ORF of variant II results from splicing of exon Bla to exon Blb which in turn is spliced to exon Alb and through this splicing to the rest of the exons within this gene. Remarkably, this splicing occurs even though exons Bla and Blb are located >45 Kb upstream of exons Ala and Alb. Our results also show that transcription starting at exons Bla and Blb is under the control of a separate and bidirectional promoter (promoter B). Exons Bla and Blb are located on the sense DNA strand within the complement C3 gene locus which is encoded on the antisense strand. This promoter is less efficient than the downstream promoter (promoter A) in regulating transcription at least in the context of reporter gene and primer extension assays. However, in these same contexts, this region of DNA sequence in the reverse orientation is markedly more efficient in driving transcription of an unidentified gene. Deletion of specific regions of sequence within this promoter have different effects depending upon the orientation (forward or reverse) within the reporter gene construct.

[A case of metastatic colon carcinoma in which a continuous intrahepatic artery-infusion of 5-FU leucovorin and cisplatin, and systemic chemotherapy with CPT-11 was very effective]

We report a patient with metastatic colon carcinoma who was treated effectively with a continuous intrahepatic artery-infusion of 5-FU, Leucovorin and cisplatin, and systemic chemotherapy with CPT-11. A 50-year-old man was diagnosed as having well differentiated adenocarcinoma of the sigmoid colon with multiple liver metastases in March, 1997. Left hemicolectomy and subsequent catheterization into the common hepatic artery via the gastroduodenal artery were performed in April, 1997. He was treated with 3 courses of continuous intrahepatic artery-infusion of 5-FU, Leucovorin and cisplatin, and two courses of systemic chemotherapy with CPT-11 during hospitalization, followed by 6 courses of a similar intraarterial therapy in an outpatient setting. Reinstallation of the catheter into the hepatic artery via the femoral artery was performed because of occlusion of the reservoir. During the 6th course of intraarterial therapy, diarrhea, nausea, and vomiting appeared and angiography revealed a narrowing of the hepatic artery. Therefore, the intrahepatic artery-infusion therapy was reinitiated with doses of 5-FU, Leucovorin and cisplatin reduced to approximately 80%. After 5 courses of this therapy, the computed tomography scan showed a marked decrease in the size of the metastatic hepatic lesions by 90%, and the serum level of CEA decreased from 657.7 ng/ml to 4.5 ng/ml. No severe side effects were seen during the treatment. Though multiple lung metastases were indicated during the intrahepatic artery-infusion therapy, both the liver and lung metastases have been well controlled with continuous intrahepatic artery-infusion chemotherapy and systemic chemotherapy. The continuous intrahepatic arterial infusion of 5-FU, leucovorin and cisplatin appears to be very effective for the treatment of colon carcinoma with liver metastasis without reducing the quality of life.

Amiloride-sensitive pressure-induced myogenic contraction in rat cerebral artery

The inhibitory action of amiloride on the pressure-induced contraction was assessed in isolated rat cerebral artery. The artery was mounted in an arteriograph, and the change in intracellular Ca2+ concentration ([Ca2+]i) and vessel diameter were simultaneously measured. The contractile response elicited by intraluminal pressurization was independent of endothelium, i.e. myogenic in nature, and abolished by nicardipine, a Ca2+ antagonist or by removal of extracellular Ca2+, and was potentiated by 25 mM KCl. Cyclopiazonic acid and thapsigargin, inhibitors of the Ca2+-ATPase pump of the sarcoplasmic reticulum, and a protein kinase C inhibitor calphostin C did not suppress the pressure-induced contraction. Amiloride, a putative stretch-activated cation channel blocker, attenuated with an IC50 (50% inhibitory concentration) of about 3 microM the increase in [Ca2+]i and contractile activity in response to pressure, whereas the drug showed no apparent effect on the contraction produced by high KCl or 9,11-dideoxy-11alpha,9alpha-epoxymethano prostaglandin F2alpha (U46619). Furthermore, amiloride (100 microM) did not significantly affect intracellular pH in the artery. In spite of its multiple pharmacological actions, it seems possible that amiloride is a useful alternative tool at the cellular or tissue level to study the mechanotransduction mechanisms involved in the pressure-induced contraction in rat cerebral artery.

[A case of advanced ovarian clear cell adenocarcinoma responding to cisplatin-cyclophosphamide and paclitaxel-carboplatin]

We report a case of stage IV ovarian clear cell adenocarcinoma successfully controlled by a combination of cisplatin-cyclophosphamide (CP) and paclitaxel-carboplatin (TJ). A 64-year-old female with advanced ovarian cancer and pleural effusion underwent 4 courses of combination chemotherapy with CP. The giant ovarian tumor showed a relative reduction in size and the pleural effusion disappeared. Serum CA-125 levels and CA 19-9 levels markedly decreased. Thus, the patient underwent a total hysterectomy and bilateral salphingoophorectomy. During the operation, a giant ovarian clear cell adenocarcinoma was found, but there was no peritoneal dissemination and no cancer cells in her peritoneal fluid. Thereafter, she underwent 3 courses of combination chemotherapy with TJ. She has had 13 months of stable, tumor-free survival since the operation and normal serum CA-125 and CA 19-9 levels. Ovarian clear cell adenocarcinoma generally responds poorly to cisplatin and carboplatin, but in combination chemotherapy with paclitaxel-carboplatin these may be effective.

Organization and structure of the mouse gamma-glutamyl hydrolase gene and the functional identification of its promoter

The organization and structure of the murine GH gene encoding gamma-glutamyl hydrolase were determined. The murine GH gene spans 24kb and was found to be distributed in nine exons. The intron/exon coding junctions delineated conformed to the GT-AG rule. The 5' UTR and 3' UTR along with some coding sequences were incorporated in exons 1 and 9, respectively, whereas exons 2-8 incorporated only coding sequence. A relatively GC-rich region of the genome 5' of exon 1 was distinctly promoter-like and encoded a number of putative cis-acting elements, including six Sp1 sites known to be involved in the regulation of transcription but no TATA sequence motif. Primer extension analysis of this region with mouse liver and S180 cell mRNA revealed several tsps within the region encompassing the Sp1 sites. Functional analysis of this 5' upstream region of sequence was carried out by inserting it into the pGL3 reporter gene vector for transfection into NIH3T3 cells. The transcription of the luciferase gene that resulted in these cells established the identity of this region as an active promoter for the mouse GH gene.

Tyrosine phosphorylation of STAT3 by leptin through leptin receptor in mouse metaphase 2 stage oocyte

Leptin is the product of the obese gene (ob), and is secreted in plasma from mature adipocytes. It has been recently reported that leptin is synthesized in granulosa and cumulus cells within the follicle of the ovary, and is present in mature human oocytes, suggesting possible roles of leptin in several aspects of pre- and post-ovulatory follicular development. On the other hand, STAT (Signal Transducer and Activator of Transcription) transcription factors are involved in leptin-associated signal transduction. In this report, we studied the expression of leptin receptor and STAT3 activation by leptin in metaphase 2 stage (M2) oocytes. Reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblotting showed that mRNA and protein of leptin receptor were expressed in M2 stage oocyte. Leptin at 15 ng/ml, the concentration observed in follicular fluid, caused tyrosine phosphorylation of STAT3 in mouse M2 stage oocytes. These results suggest possible roles of leptin in several aspects during oocyte maturation by activating the STAT signal transduction pathway.

v-src induces cisplatin resistance by increasing the repair of cisplatin-DNA interstrand cross-links in human gallbladder adenocarcinoma cells

Activation of Src, which has an intrinsic protein tyrosine kinase (PTK) activity, has been demonstrated in human solid tumors, such as colorectal and breast cancers. To investigate the role of activated Src in drug resistance, we evaluated the effect of v-src on the resistance to various anti-cancer drugs using v-src-transfected HAG-1 human gallbladder adenocarcinoma cells. Compared with parental or mock-transfected HAG-1 cells, v-src-transfected HAG/src3-1 cells showed a 3.5-fold resistance to cis-diamminedichloroplatinum (II) (CDDP) but not to doxorubicin, etoposide or 5-fluorouracil. By contrast, activated H-ras, which acts downstream of src, failed to induce resistance to either of these drugs. Furthermore, wortmannin, a phosphatidylinositol (PI) 3-kinase inhibitor, and H7, a protein kinase C (PKC) inhibitor, did not alter CDDP resistance. Evaluation of the kinetics of the removal of DNA interstrand cross-links (ICLs), measured by alkaline elution, showed a significant increase in this removal in HAG/src3-1 cells as compared with mock-transfected cells, though no differences were found in the formation of DNA ICLs between these cell lines. CDDP resistance in v-src-transfected cells was reversed, if not completely, by either herbimycin A or radicicol, specific inhibitors of Src-family PTKs, suggesting that Src tyrosine kinase activity induces CDDP resistance. Moreover, significant reduction in the repair of CDDP-induced DNA ICLs was observed upon treatment with radicicol. The intracellular glutathione content and mRNA expression of topoisomerase II and metallothionein were virtually identical between these cell lines, except for topoisomerase I mRNA. Our data strongly suggest that the ability of activated src, but not ras, to induce CDDP resistance is mediated by augmentation of DNA repair through Src to downstream signal-transduction pathways distinct from either the Ras, PI 3-kinase or PKC pathway.

SNAP-25 is essential for cortical granule exocytosis in mouse eggs

Synaptosome-associated protein of 25 kDa (SNAP-25) has been shown to play an important role in Ca2+-dependent exocytosis in neurons and endocrine cells. During fertilization, sperm-egg fusion induces cytosolic Ca2+ mobilization and subsequently Ca2+-dependent cortical granule (CG) exocytosis in eggs. However, it is not yet clear whether SNAP-25 is involved in this process. In this study, we determined the expression and function of SNAP-25 in mouse eggs. mRNA and SNAP-25 were detected in metaphase II (MII) mouse eggs by RT-PCR and immunoblot analysis, respectively. Next, to determine the function of SNAP-25, we evaluated the change in CG exocytosis with a membrane dye, tetramethylammonium-1,6-diphenyl-1,3,5-hexatriene, after microinjection of a botulinum neurotoxin A (BoNT/A), which selectively cleaves SNAP-25 in MII eggs. Sperm-induced CG exocytosis was significantly inhibited in the BoNT/A-treated eggs. The inhibition was attenuated by coinjection of SNAP-25. These results suggest that SNAP-25 may be involved in Ca2+-dependent CG exocytosis during fertilization in mouse eggs.

Interferon-alpha and -gamma inhibit the growth and neoplastic potential of v-src-transformed human epithelial cells by reducing Src tyrosine kinase activity

To investigate whether interferons (IFNs) selectively suppress the growth of solid tumor cells with elevated protein tyrosine kinase (PTK) activity, we evaluated the effect of recombinant IFN-alpha2a and IFN-gamma on the proliferative and neoplastic potentials triggered by p60v-src using v-src-transformed HAG-1 human epithelial cells. When compared with control cells harboring the pSV2neo gene, the monolayer growth of v-src-transformed cell lines was inhibited by both recombinant IFNs, in a dose-dependent manner, whereas growth of ras-transfected cell lines was not affected. Moreover, IFNs markedly reduced the clonogenic growth of v-src-transformed cells in soft-agar rather than monolayer growth, suggesting the preferential activity of IFNs on anchorage-independent growth. Pretreatment of cells with Src or the Src-like PTK inhibitor herbimycin A or radicicol, alleviated dose-dependently the growth-inhibitory activity of IFN-alpha2a against v-src-transformed cells, suggesting that IFNs may share a common inhibitory pathway with Src PTK inhibitors. Accordingly, like herbimycin A, IFNs were found to reduce tyrosine phosphorylation of p60v-src and suppressed in vitro p60v-src kinase activity in v-src-transformed cells. Our data, together with the fact that IFNs inhibit the growth potential driven by Src but not by activated Ras, suggest that inhibition of signal transduction pathway through Src to downstream transduction events may be a primary mechanism of IFN-induced anti-prolifeative and anti-tumoral activity.

Rab3B is essential for GnRH-induced gonadotrophin release from anterior pituitary cells

Gonadotrophin-releasing hormone (GnRH) induces the release of gonadotrophins via an increase in cytosolic Ca2+ concentration ([Ca2+]). Rab3B, a member of the small GTP-binding protein Rab family, is known to be involved in Ca(2+)-regulated exocytosis in pituitary cells. However, it is not known whether Rab3B functions in the physiological process regulated by GnRH in gonadotrophs. In this study using antisense oligonucleotide against Rab3B (AS-Rab3B) we determined that Rab3B is involved in GnRH-induced gonadotrophin release. Rab3B immunopositive cells were reduced in 24% of pituitary cells by AS-Rab3B. This treatment did not affect the population of gonadotrophs or the intracellular contents of gonadotrophins. However, AS-Rab3B significantly inhibited the total amount of basal and GnRH-induced gonadotrophin released from pituitary cells. These results show that Rab3B is involved in basal and GnRH-induced gonadotrophins release but not the storage of gonadotrophins. Next, the changes in [Ca2+] and exocytosis in gonadotrophs treated with AS-Rab3B were compared among Rab3B-positive and -negative cells. The change in [Ca2+] was not different in the two groups, but exocytosis was significantly inhibited in Rab3B-negative cells. These results suggest that Rab3B is essential for GnRH-regulated exocytosis downstream of cytosolic Ca2+ in gonadotrophs.

Expression of Rab3A in the cortical region in mouse metaphase II eggs

Rab3A, a member of the small GTP-binding protein superfamily, has been implicated in regulated exocytosis at presynapses. At fertilization, sperm-egg fusion induces cytosolic calcium mobilization and cortical granule (CG) exocytosis in the egg. However, it is not yet clear whether Rab3A is involved in this process. We previously reported that Rabphilin-3A functions in calcium-dependent CG exocytosis. Rabphilin-3A is known to bind with Rab3A, Rab3B, and Rab3C. In this study, we clarified which member of the Rab3 was expressed in mouse metaphase II eggs. Messenger RNA encoding Rab3A but not Rab3B or Rab3C, was detected in unfertilized metaphase II eggs by RT-PCR. Rab3A protein was also detected in unfertilized metaphase II eggs by immunoblot analysis. Next the expression and the localization of Rab3A in eggs at various stages of development were determined by immunofluorescence analysis using confocal laser scanning microscopy. Rab3A protein was specifically distributed in the cortical region in eggs from before fertilization to the two-cell stage. However, it was not detected at the three- or four-cell stage 40 hr after fertilization. These results suggest that Rab3A may function with Rabphilin-3A in CG exocytosis.

Bihormonal cells secreting both prolactin and gonadotropins in normal rat pituitary cells

The present study was designed to characterize bihormonal cells in rat pituitary cells which secrete PRL and gonadotropins. This was done by using sandwich cell immunoblot assay (CIBA) and reverse hemolytic plaque assay (RHPA) in combination with immunocytochemistry (ICC) and by measuring the intracellular free calcium concentration ([Ca2+]i). The result of the experiment with sandwich CIBA revealed that the populations of LH- and FSH-secreting cells in the PRL-secreting cells were 6.23% and 5.91%, respectively, and the populations of the PRL secreting cells in the LH- and FSH-secreting cells were 18.4% and 15.5%, respectively. Additional studies by the combined techniques of RHPA with ICC revealed that the populations of LH- and FSH-containing cells in the PRL secreting cells were 4.43% and 2.40%, respectively, which were consistent with the results of Sandwich CIBA. Some of the PRL-secreting cells determined by RHPA showed responsiveness to TRH and GnRH in [Ca2+]i. These results suggest that bihormonal cells which secrete both PRL and LH, or both PRL and FSH are present in the normal rat pituitaries.

Specific attenuation of the pressure-induced contraction of rat cerebral artery by herbimycin A

In order to determine whether protein tyrosine kinase mechanisms are involved in pressure-induced contraction, we compared effects of three structurally unrelated tyrosine kinase inhibitors and orthovanadate, a tyrosine phosphatase inhibitor, on the pressure-induced contraction of the posterior cerebral artery isolated from rats. The change in vessel diameter was continuously measured with a width analyzer. Herbimycin A inhibited the pressure-induced contraction, while it only slightly inhibited contractions produced by potassium chloride or 9,11-dideoxy-11alpha,9alpha-epoxymethano prostaglandin F2alpha (U46619). Genistein inhibited not only the pressure-induced contraction but also the U46619-induced one. Tyrphostin 23 significantly attenuated contractions in response to three different stimuli, i.e., pressure, potassium chloride and U46619. Orthovanadate potentiated the pressure-induced contraction. These results suggest that herbimycin A is a specific and potent inhibitor of the pressure-induced contraction and that a protein tyrosine kinase mechanism may play an important role in the genesis of the pressure-induced contraction of the rat cerebral artery.

Involvement of a sperm protein sensitive to sulfhydryl-depleting reagents in mouse sperm-egg fusion

Effects of various sulfhydryl (SH)-depleting reagents on sperm-egg fusion were demonstrated. When sperm were treated with three plasma membrane-permeable SH-depleting reagents, N-ethyl-maleimide, sodium tetrathionate and 5,5'-dithiobis (2-nitro-benzoic acid), the rates of cleavage of eggs were significantly lower than those with control sperm. Neither the motility, penetration of the zona pellucida, acrosomal status of the sperm, nor sperm-egg binding was affected by the SH-depleting reagents. Fusion of sperm and zona-free egg was estimated by the sperm nuclear incorporation into the eggs, intracellular calcium mobilization, and cortical granule exocytosis in the eggs. Sperm-egg fusion was blocked dose-dependently when sperm were exposed to membrane-permeable SH-depleting reagents, but was not blocked by a membrane-impermeable SH-depleting reagent, eosin-5-maleimide. Blockage of fusion by sodium tetrathionate was completely reversed by an SH-reductant, dithiothreitol. These results suggest that a protein which is sensitive to SH-depleting reagents may play an important role in mouse sperm-egg fusion and that the functional SH region of the protein may be located at an intracellular site.

Involvement of SNAP-25 in TRH-induced exocytosis in pituitary GH4C1 cells

The synaptic membrane protein synaptosomal-associated protein (SNAP-25) has recently been implicated as one of the key proteins involved in exocytotic membrane fusion in neurons. However, the role of SNAP-25 in pituitary hormone release is not known. In this study, we determined that SNAP-25 is involved in regulated exocytosis in the clonal pituitary cell line GH4C1. SNAP-25 messenger RNA and protein were detected in GH4C1 cells by RT-PCR and immunoblot analysis, respectively. Immunofluorescence analysis indicated that SNAP-25 protein was localized in the plasma membrane. Next, to determine the function of SNAP-25 in GH4C1 cells, specific inhibitors of SNAP-25, botulinum neurotoxin (BoNT)/A or /E, and antisense SNAP-25 oligonucleotide were used. Neither BoNT/A nor BoNT/E affected thyrotropin-releasing hormone (TRH)-induced cytosolic Ca2+ increase, but both inhibited TRH-induced exocytosis. Moreover, they dose-dependently inhibited TRH-induced prolactin release. The introduction of antisense oligonucleotide into the cells also inhibited TRH-induced prolactin release. These results suggest that SNAP-25 is involved in regulated exocytosis in GH4C1 cells.

[Cell signaling and CDDP resistance]

Although evidence exists that intracellular signaling through oncogene products may play a role in the resistance of anticancer drugs, the underlying mechanism remains to be clarified. Using a HAG-1 cell line as a human epithelial model, we have studied the alteration of drug sensitivity and determined the mechanism of resistance induced in HAG-1 cells transfected with various oncogenes, which are highly expressed and activated in human cancers. Non-tumorigenic HAG-1 cells acquired fully neoplastic phenotype and resistance to Cisplatin (CDDP) by transfection with v-src but not by activated ras oncogene. The src-transfected cells showed a significant decrease in the formation of CDDP-induced DNA interstrand cross-links with rapid removal of these lesions. Upon treatment with src kinase inhibitors, the level of CDDP resistance and the rate of removal were both reduced in src-transformed cells. These results suggest the ability of v-src oncogene product but not ras to induce CDDP resistance by modulating the certain DNA repair pathway. Thus, intracellular signaling may be the appropriate target for strategies to reverse the drug resistance. In this review, we discuss the role of oncogenes important for signal transduction such as ras and those with protein tyrosine kinase activity in the drug resistance.

Inhibition by 5-fluorouracil of ERCC1 and gamma-glutamylcysteine synthetase messenger RNA expression in a cisplatin-resistant HST-1 human squamous carcinoma cell line

Pretreatment of 5-fluorouracil (5-FU), but not posttreatment, has been shown to augment the cytotoxicity of cisplatin (CDDP) or even circumvent CDDP resistance by inhibiting repair of platinum-DNA interstrand crosslinks as well as by reducing the cellular glutathione (GSH) contents in CDDP-resistant HST-1/CP0.2 human squamous carcinoma cells. Because exogenous thymidine, which compensates for 5-FU-mediated inhibition of de novo DNA synthesis via salvage pathway, did not affect this schedule-dependent synergism, the modulatory effect of 5-FU on CDDP resistance would be attributed to the 5-FU-induced RNA damage. We therefore examined the effect of 5-FU on the steady-state levels of messenger RNA (mRNA) of a human excision repair gene ERCC1 and gamma-glutamylcysteine synthetase (gamma-GCS) gene coding for a rate-limiting enzyme for GSH synthesis. The HST-1/ CP0.2 cells were found to have significantly more mRNA expression of these respective genes than do parental HST-1 cells. In these cells, 5-FU pretreatment progressively inhibited mRNA expression of both ERCC1 and gamma-GCS after removal of 5-FU, without affecting glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNA. A maximal mRNA suppression was observed at 48 h posttreatment. Such 5-FU-induced suppression of mRNA transcripts of these genes seems to be consistent with its inhibitory activity on DNA repair capacity and cellular GSH contents. In contrast, 5-FU did not reduce the level of glutathione-S-transferase-pi (GST-pi) or DNA topoisomerase 1 mRNA. Although not convinced, our data suggest that 5-FU, when incorporated into RNA, may inhibit both GSH synthesis and repair of platinum-DNA adducts by downregulating the ERCC1 and gamma-GCS genes, thereby enhancing antitumor activity of CDDP and reversing resistance to CDDP in HST-1/CP0.2 cells.

[A case of colon cancer with local recurrence successfully treated by systemic and local intra-arterial chemotherapy using a combination of 5-fluorouracil, interferon-alpha 2A, leucovorin and carboplatin]

A 59-year-old man with colon cancer was diagnosed as having a local recurrence of the disease, forming a huge intra pelvic tumor, accompanied by pulmonary metastasis 16 months after hemicolectomy. He received alternate systemic and local chemotherapy consisting respectively of a 5-day course of continuous infusion of 5-FU 600 mg/m2/day, bolus injection of leucovorin (LV) 20 mg/m2/day, intramuscular injection of interferon (IFN)-alpha 2a 6 x 10(6) IU/day, and intra-arterial administration of 5-FU, LV and carboplatin using reservoir catheter through pudendal artery, each repeated every 3 weeks. After 6 systemic and 8 local treatments, metastatic lesions disappeared and the intra-pelvic tumor shrunk by 62%, indicating a partial response. The patient then underwent dissection of the intra-pelvic tumor. Pathological examination indicated a curative resection. Alternate systemic and local intra arterial chemotherapy using a combination of 5-FU, LV, IFN and and carboplatin is highly promising for metastatic colorectal cancer with local recurrence.

The role of mitogen-activated protein kinase in oxytocin-induced contraction of uterine smooth muscle in pregnant rat

Oxytocin causes the rapid tyrosine phosphorylation of mitogen-activated protein (MAP) kinase in both human and rat puerperal uterine myometrial cultured cells. The potential role of the MAP kinase pathway in oxytocin action was investigated with the specific MAP kinase kinase (MEK) inhibitor, PD98059. Oxytocin stimulation of the tyrosine phosphorylation of MAP kinase in both human and rat cultured puerperal uterine cells was abolished by pretreatment of the cells with MEK inhibitor in a dose-dependent manner. Although MEK inhibitor had no effect on oxytocin-induced intracellular Ca2+ mobilization in either pregnant human or pregnant rat uterine cells, it partly inhibited oxytocin-induced pregnant rat uterine contraction in a dose-dependent manner. These results suggest that MAP kinase pathway may have some important roles in oxytocin-induced uterine contraction.

Involvement of Rabphilin-3A in cortical granule exocytosis in mouse eggs

Rabphilin-3A is a putative target protein for Rab3A, a member of the small GTP-binding protein superfamily that has been suggested to play a role in regulated exocytosis in presynapses. In this study we determined the expression and the function of Rabphilin-3A in mouse eggs at fertilization. Rabphilin-3A mRNA and protein were detected by reverse transcriptase-PCR and immunoblot analysis, respectively, in metaphase II mouse eggs. Immunofluorescence analysis showed that Rabphilin-3A protein was distributed in the cortical region in eggs. Sperm induces cortical granule (CG) exocytosis via an increase in cytosolic Ca2+ at fertilization. We microinjected the NH2- or COOH-terminal fragment of recombinant Rabphilin-3A into metaphase II eggs. Neither treatments altered the sperm-induced cytosolic Ca2+ increase, but both inhibited CG exocytosis in a dose-dependent manner. The NH2-terminal fragment was more effective than the COOH-terminal fragment. Full-length Rabphilin-3A did not affect CG exocytosis, but it attenuated the inhibition of CG exocytosis by the NH2-terminal fragment. These results show that Rabphilin-3A is involved in Ca(2+)-dependent CG exocytosis at fertilization in mouse eggs.

Reactive oxygen species block sperm-egg fusion via oxidation of sperm sulfhydryl proteins in mice

The effects of reactive oxygen species (ROS) on mouse sperm-egg fusion were determined. Sperm were treated with superoxide and hydrogen peroxide generated by addition of xanthine oxidase (XO: 10-200 mlU/ml) to hypoxanthine (HX: 1 mM). While XO at concentrations higher than 100 mlU/ml decreased the motility and lipid peroxidation of sperm, XO at less than 50 mlU/ml had no such effect. However, 20-50 mlU/ml XO significantly suppressed sperm fusion with zona-free eggs. Two ROS scavengers, superoxide dismutase and catalase, attenuated the inhibition of sperm-egg fusion by HX-XO. The sulfhydryl (SH) reductant, dithiothreitol, also reversed the inhibition. The sperm SH-rich fusion-related proteins were highly sensitive to ROS. These results suggest that ROS at low concentrations may inhibit sperm-egg fusion via oxidation of the SH-proteins in the sperm membrane, without causing loss of motility.

[Comparative trial of granisetron alone and granisetron plus methylprednisolone for prevention of nausea and vomiting during cancer chemotherapy]

A crossover clinical trial between granisetron alone and granisetron combined with methylprednisolone (MPL) was undertaken for the prevention of nausea and vomiting during chemotherapy, including cisplatin, in 12 patients with advanced primary and metastatic lung cancer. The antiemetic effect was obtained in 91.7% (11/12 cases) of patients receiving granisetron alone compared to 100% (12/12 cases) of patients receiving the combination of granisetron plus MPL. Complete control of anorexia was achieved in 91.6% (11/12 cases) of patients receiving the combination compared to 58.3% (7/12 cases) of patients receiving granisetron alone. Moreover there was a significant improvement of delayed clinical symptoms including nausea, vomiting, and anorexia in the patients receiving the combination of granisetron plus MPL. Our data suggest that the antiemetic effect of the combination of granisetron plus MPL is superior to granisetron alone in patients receiving cancer chemotherapy.

Schedule-dependent reversion of acquired cisplatin resistance by 5-fluorouracil in a newly established cisplatin-resistant HST-1 human squamous carcinoma cell line

In vitro continuous stepwise exposure of HST-1 human squamous carcinoma cell line to cisplatin (CDDP) for 12 months resulted in a 3.5-fold stably resistant subline designated HST-1/CP0.2. Compared with parental cells, this cell line showed a 1.8-fold increase in cellular glutathione (GSH) and a 50% reduction in initial numbers of DNA interstrand cross-links (ICLs), despite similar levels of intracellular platinum accumulation. Evaluation of the kinetics of DNA ICL removal at nearly equivalent levels of DNA ICL formation indicated that HST-1/CP0.2 cells appeared to remove DNA ICLs more rapidly than do HST-1 parental cells. Thus, both elevated cellular GSH and increased DNA repair capacity would be the major factors contributing to CDDP resistance. Pretreatment of HST-1/CP0.2 cells with 5-FU, with drug-free intervals of 24 to 48 hr before exposure to CDDP, completely reversed CDDP resistance, or even increased the sensitivity to a level greater than that of parental cells, whereas the opposite sequence had no effect on resistance. In parallel with augmentation of the cytotoxicity, the levels of cellular GSH were significantly reduced over 48 hr by 5-FU pretreatment. However, depletion of cellular GSH using buthionine sulfoximine resulted in partial reversal of CDDP resistance, indicating that reduction of cellular GSH alone is not sufficient for complete reversal of CDDP resistance. Our data, together with evidence that 5-FU modulates the repair of platinum-DNA cross-links, suggest that schedule-dependent, complete reversal of CDDP resistance by 5-FU might be attributed to its inhibitory effects on both GSH levels and the repair of platinum-DNA adducts. Thus, optimization for the drug administration schedule is important when aiming at therapeutic synergy and circumvention of acquired CDDP resistance.