( This ( ( ( ( is ( ( the ( less threatening ) ) ( of ( the ( two phases ) ) ) ) ) , ) ( because ( ( once ( ( the melanoma ) ( grows ( into ( ( ( ( ( ( the dermis ) -LRB- ) ( lower skin ) ) -RRB- ) and ) ( underlying structures ) ) ) ) ) ) ( , ( ( the prognosis ) ( becomes worse ) ) ) ) ) ) . ) )
(ROOT (S (NP (DT This)) (VP (VBZ is) (NP (NP (DT the) (ADJP (RBR less) (JJ threatening))) (PP (IN of) (NP (DT the) (CD two) (NNS phases)))) (, ,) (SBAR (IN because) (S (SBAR (IN once) (S (NP (DT the) (NN melanoma)) (VP (VBZ grows) (PP (IN into) (NP (NP (NP (DT the) (NNS dermis)) (-LRB- -LRB-) (NP (JJR lower) (NN skin)) (-RRB- -RRB-)) (CC and) (NP (VBG underlying) (NNS structures))))))) (, ,) (NP (DT the) (NN prognosis)) (VP (VBZ becomes) (ADJP (JJR worse)))))) (. .)))
This is the less threatening of the two phases, because once the melanoma grows into the dermis (lower skin) and underlying structures, the prognosis becomes worse.
(ROOT (S (NP (JJS Most) (NN skin) (NNS structures)) (VP (VB originate) (PP (IN in) (NP (DT the) (NNS dermis)))) (. .)))