Correlation between apparent diffusion coefficients and HER2 status in gastric cancers: pilot study

Zhengyang Zhou¹, Jian He¹, Song Liu¹, and Weibo Chen²

¹Department of Radiology, Drum Tower Hospital, School of Medicine, Nanjing University, Nanjing, China, People's Republic of, ²Philips Healthcare Greater China, Shanghai, China, People's Republic of

Synopsis

Forty-five patients with gastric cancer underwent DWI prior to surgery to evaluate whether ADC value correlates with the HER2 status. HER2 status was compared among tumors with various histopathological features. Meanwhile, the ADC values of gastric cancers with positive and negative HER2 were compared. The mean ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The minimal ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors. The ADC values of gastric cancer correlate with the HER2 status. DWI can predict HER2 status and help in tailoring therapy for gastric cancer.

Purpose: To evaluate whether apparent diffusion coefficient (ADC) value of gastric cancer obtained from diffusion weighted imaging (DWI) correlates with the HER2 status.

Methods: Forty-five patients, who had been diagnosed with gastric cancer through biopsy, were enrolled in this IRB-approved study. Each patient underwent a DWI (b values: 0 and 1,000 sec/mm2) prior to surgery (curative gastrectomy or palliative resection). Postoperative microscopic findings, HER2 status by immunohistochemical analysis and fluorescence in situ hybridization (FISH) were obtained. HER2 status was compared among gastric cancers with various histopathological features using the chi square test. The ADC values of gastric cancers with positive and negative HER2 were compared using the student t test.

Results: A weak yet significant correlation was observed between the mean ADC values and HER2 status (r = 0.312, P = 0.037) and scores (r = 0.419, P = 0.004). The mean ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors (1.211 vs. 0.984 mm2/s, P = 0.020). The minimal ADC value of HER2-positive gastric cancers was significantly higher than those of HER2-negative tumors (1.105 vs. 0.905 × 10−3 mm2/s, P = 0.036).

Conclusions: In this pilot study, we have demonstrated that the ADC values of gastric cancer correlate with the HER2 status. Future research is warranted to see if DWI can predict HER2 status and help in tailoring therapy for gastric cancer.

Acknowledgements

No acknowledgement found.

References

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2. Bang YJ, Van Cutsem E, Feyereislova A, et al. Trastuzumab in combination with chemotherapy versus chemotherapy alone for treatment of HER2-positive advanced gastric or gastrooesophageal junction cancer (ToGA): a phase 3, open-label, randomized controlled trial. Lancet. 2010;376:687–97.

3. Fisher SB, Fisher KE, Squires MH, et al. HER2 in resected gastric cancer: is there prognostic value? J Surg Oncol. 2014;109:61–6.

4. Liu S, Guan W, Wang H, Pan L, Zhou Z, Yu H, et al. Apparent diffusion coefficient value of gastric cancer by diffusion-weighted imaging: Correlations with the histological differentiation and Lauren classification. Eur J Radiol. 2014;83:2122–8.

5. Costantini M, Belli P, Distefano D, et al. Magnetic resonance imaging features in triple-negative breast cancer: comparison with luminal and HER2-overexpressing tumors. Clin Breast Cancer. 2012;12:331–9.

Figures

A man with gastric cancer, at stage IIIA .(a) shows the lesion with remarkably high signal intensity in antrum. An oval ROI is placed within the solid part of the lesion in corresponding ADC map (b), which shows restricted mean and minimal ADC values as 1.148 and 0.970 respectively. H & E staining, (c) proves moderately differentiated adenocarcinoma. HER2 immunohistochemical assay (d) shows complete and intense circumferential membrane staining in >10 % of tumor cells (score 3+).

A 58-year-old man with gastric cancer. (a) shows a hyperintense lesion in antrum. An oval ROI is placed within the solid part of the lesion in corresponding ADC map (b), which shows restricted mean and minimal ADC values as 0.918 and 0.867. Photomicrograph (c) reveals signet ring cell carcinoma. HER2 immunohistochemical assay (d) shows no membrane staining is observed (score 0)

Fig. 3

Table 1 Mean and min ADC values (×10−3 mm2/s) of gastric cancers with different

Table 2 Histopathological features in gastric cancers with different HER2 status

Proc. Intl. Soc. Mag. Reson. Med. 24 (2016)

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