It is a cause close to Horsman's heart having being diagnosed with testicular cancer when he was just 19.
Having had the tumour removed and undergoing a series of chemotherapy, Horsman was forced to battle with secondary cancer of his lymph nodes two years later.
He has been in remission for more than decade which has seen him embark on a successful rugby career with Bath, Bridgend, Celtic Warriors, Worcester - where he is now in his fifth season - and Wales having won 14 caps for the Dragons.
Horsman is eager to play a part in raising the profile of the cause and has accepted an invite to judge the month-long moustache grow after being contacted by Warriors season-ticket holder and Solihull Round Table member Brad Parkes.
"I think it's a brilliant and crazy way to not only raise funds but also the profile of male cancers," he said.
"I think what Round Table are doing is to be commended and I was more than happy to support what they are doing.
"Growing moustaches certainly gets people talking because it so visual and that gives you the opportunity to talk more about the cause because male cancers don't get that much publicity and yet we do need to raise awareness.
"Men are not very good at talking about these things and do get embarrassed but having been through it I'm not because I want people to understand and take an interest.
"I know from experience that when I was diagnosed I felt very isolated and when I was stuck in hospital having treatment I felt very low.
"These cancers are life-threatening but I came through it after being diagnosed in the early stages. There is a very high success rate if it's caught early and without doubt that saved my life.
"I contracted secondary cancer and by the grace of God I managed to beat it and since then I have been fortunate to come back stronger from it and play international rugby."
The moustache grow will conclude on March 5 with more than 40 Round Tablers from the City of Birmingham, Moseley, Bromsgrove, Redditch, Shirley, Solihull, Alcester and Droitwich Tables converging on Kings Heath Cricket Club for a Wild West themed finale.
It is expected that the month-long effort will raise in the region of £3,000 for Orchid, three times the initial target.
For further details please visit www.bmycharity.com/moseleyroundtable