Response on: Comments on “Salivary 8-hydroxy-2-deoxyguanosine, malondialdehyde, vitamin C, and vitamin E in oral pre-cancer and cancer: diagnostic value and free radical mechanism of action”

Abstract

Dear Editor:In response to comment [1] on our published article [2], we would like to point out that cancer has indeed different pathways involving oxidative stress, hormonal factors, inflammation, and others. As such, cancer is considered a multi pathway disease, involving various diagnostic markers. In this way, salivary biomarkers may be multiple (8-hydroxy-2-deoxyguanosine, malondialdehyde (MDA), vitamin C, and vitamin E) but at the same time also present some further challenges to act as diagnostic biomarkers of oral pre-cancer and cancer.Variations in salivary MDA level are caused by different collection time, different storage time, time from collection to analysis or collection to storage, and analysis methods. In the present study, a standardized method of collection was followed, i.e., drooling method with minimum time for storage and standardized analysis parameters, in order to enable reproducing results. At the same time, and in combination with other biomarkers, salivary MDA as an oxidative biomarker may be considered a reliable biomarker for oral pre-cancer and cancer [3][4][5]. Considering both aforementioned factors, it can be stated that salivary MDA may be a reliable biomarker if standardized methods of collection, storage, and analysis are followed [3][4][5].

Malondialdehyde and Nitrous oxide as Salivary Biomarkers for Malignant and Premalignant Oral lesions

“…In agreement with our results (Kaur, Politis and Jacobs, 2016) reported that MDA levels were significantly higher in OSCC with sensitivity and specificity of 61% and 58% versus control. On comparing MDA of potentially malignant lesion versus control, both sensitivity and specificity were 55% while on comparing OSCC and OPML it was only 43% and 45% for sensitivity and specificity respectively.…”

“…This power analysis used MD level as the primary outcome. The effect size (f = 0.34) for comparison between the five groups was calculated based upon the results of (Kaur, Politis and Jacobs, 2016). Using alpha (α) level of (5%) and Beta (β) level of (20%) i.e.…”